# The Raga and the Blast Beat *Musicians talk about energy all the time, and they are not wrong—it can be measured, in events per second, in the brightness of a spectrum, in the dynamic range a recording keeps, and in the pulse of the person listening. What it is not is a frequency. No genre vibrates at one. What the nine rasas, the Doctrine of Affections and the subgenres of metal all know, in their different dialects, is how to shape it.* Music · September 2026 · 18 min · by Epimystic Canonical: https://epimystic.com/essays/the-raga-and-the-blast-beat/ Topics: sound, energy, rhythm, perception, form There is a word every musician uses and no musician can define, and it is not _soul_ or _groove_ but _energy_. The band has energy tonight. The second set lost its energy. This raga has a heavy, dark energy; that one is light. A death-metal drummer and a Dhrupad singer would both nod at the word, and neither could tell you its units. I want to find its units, because it has them, and then go further, because it also points at something they do not catch. The literal energy of a sound is its intensity, which the ear reads as loudness: about thirty decibels for a whisper, forty for a string quartet at its softest, a hundred for an orchestra at a climax, a hundred and fifteen at the barrier of a metal show. That is almost never what anyone means; the quiet opening of a symphony can be electric and a compressed pop master at full volume inert. What the word is doing, I think, is naming four measurable things at once—how loud, how fast, how bright, how much contrast—and a fifth that lives in the listener: arousal, the quantity a racing pulse and dilated pupils report. The folklore—that genres have vibrational frequencies, that A should be tuned to 432 rather than 440 hertz, that certain hertz heal—takes the fifth thing and pretends it is a property of the first. The codex has [dealt with those numbers already](https://epimystic.com/essays/the-frequencies-that-tune-us/), so I will only say that a frequency is a pitch, a pitch is not an energy, and move on to the part that is true. ## What Energy Measures Tempo is the obvious axis and the crudest. An adagio runs around sixty-six to seventy-six beats a minute, an allegro from about a hundred and twenty to a hundred and sixty-eight. Jazz takes a ballad at fifty to seventy and bebop at three hundred. Doom metal sits at forty to eighty, funeral doom at thirty to fifty, the drone bands have no tempo at all, and death metal runs from about a hundred and eighty to two hundred and sixty. But tempo misleads, because a slow tempo with dense subdivision is busier than a fast one with none. The better measure is the count of things that happen per second—onsets—and here the spread is two orders of magnitude. A Hindustani alap, unmetered, unfolds at perhaps one event a second. A swing rhythm section at a hundred and forty beats a minute, ride and hi-hat and walking bass together, puts down about seven, an orchestra in a busy tutti eight or ten, a sitar’s jhala or a bebop line ten to twelve. A blast beat—alternating snare and kick with a cymbal on every stroke, sixteenth notes at a hundred and eighty to two hundred and eighty beats a minute—delivers twelve to nineteen strikes a second, at which point the ear stops counting and hears a texture. The third axis is brightness, and it has a proper number: the spectral centroid, the frequency above and below which the energy of the spectrum is equally divided. A cello alone sits near five hundred hertz. A symphony orchestra averages around a kilohertz; a jazz quartet a little higher because of the cymbals; a rock band with distorted guitars around two; the treble-heavy production of black metal, tremolo picking and washed cymbals with the bass rolled off, up past three. Brightness is what the ear calls _sharp_ or _harsh_ or _warm_, and it is remarkably independent of the other axes. Doom is slow and dark; black metal is fast and bright; death metal is fast and mid-heavy; each pairing is a different kind of energy. *Figure: the-genre-energy-map — What the word measures when it is measured: events per second across the bottom, spectral brightness up the side, and the size of each ring for the dynamic range a typical recording keeps. Representative values; read them as regions, not points.* (drawn in the essay: https://epimystic.com/essays/the-raga-and-the-blast-beat/) The fourth axis is the one recordings have been quietly throwing away. Dynamic range is the distance between a piece’s loudest and softest moments, and in a hall it is enormous—sixty decibels or more between a pianissimo and a tutti. On a record it is a choice, and since the nineties popular music has chosen to compress it almost to nothing so that a track sounds louder than its neighbours. The scale engineers use runs from about twenty for an orchestral disc to twelve for a rock album of the seventies; Metallica’s _Death Magnetic_ in 2008 measured three, where the same band’s black album from 1991 sits at eleven. That is a loudness war in numbers: energy bought by spending contrast, until there is none left to spend.[^1] And the fifth thing, the one in the body. Psychologists of musical emotion work with two axes, valence and arousal—pleasant-to-unpleasant and calm-to-excited—and the consistent finding across fifty years of experiments is that arousal follows the four quantities above with almost embarrassing fidelity: faster, louder, brighter, busier music raises heart rate, skin conductance and reported excitement in listeners from every culture tested. Valence—mode, consonance, expectation—is harder, and bends with what you grew up hearing. So when a musician says the room has energy, the honest translation is that arousal is high—and which of the four routes got it there is the whole difference between a tanpura and a wall of amplifiers. ## Two Machines for Pouring Energy Upward The tanpura is four strings on a gourd, tuned usually to the fifth, the tonic twice and the tonic an octave below—Pa Sa Sa Sa. A male singer’s Sa sits around C sharp or D, about a hundred and forty hertz; a woman’s around A, two hundred and twenty. Nothing about that explains the sound, a shimmering cloud of harmonics that breathe and migrate as the strings ring. The explanation is the bridge: broad and curved, with a cotton thread set under each string so that the string grazes it on every cycle instead of leaving cleanly. C. V. Raman worked out in 1921 that the grazing breaks the ordinary law of the plucked string—the harmonic that ought to be silent when you pluck at its node sings out anyway—and that the bridge is, in effect, pumping energy from the fundamental up into the overtones.[^2] What the ear gets is a drone whose harmonics are individually audible to the thirtieth and beyond, with the middle of the ladder—roughly the sixth to the twelfth—lifted well above what a plain string would give. That lift is the jvari, and it is why a tanpura on one note supplies the whole raga’s frame: the fifth, the major third, the flat seventh and the ninth are all in the drone, faintly. It is a bright instrument playing a low note, and the brightness is the reference every other note is tuned to. Now the other machine. Play the bottom string of a guitar with the fifth above it—E and B, eighty-two and a hundred and twenty-four hertz, the power chord—through an amplifier driven past what it can reproduce. Clipping shears the top off every cycle, which adds harmonics of each note, and because two notes are present it also multiplies them together into sum and difference tones. The difference between a hundred and twenty-four and eighty-two is forty-one hertz, the E an octave below the one you played, and every product of the two notes lands on a multiple of forty-one. So a distorted power chord is a complete harmonic series on a note nobody played, dense all the way up until the loudspeaker cabinet rolls it off above four or five kilohertz. That is why it sounds like one enormous note, and why a third or a tritone through the same pedal turns to mud: their products do not settle into one series but land between the harmonics, and in equal temperament they beat. *Figure: the-drone-and-the-fuzz — Two non-linear devices on a logarithmic frequency axis. Above, a tanpura on D: thirty-two harmonics, the middle of the ladder lifted by the grazing bridge. Below, a distorted E power chord: every multiple of forty-one hertz, a series on a note nobody played.* (drawn in the essay: https://epimystic.com/essays/the-raga-and-the-blast-beat/) > **Both the tanpura and the fuzz pedal are machines for pouring energy up the harmonic ladder. One of them is patient about it.** Put those two spectra side by side and you have most of the argument. The drone and the distorted chord are physical cousins that produce opposite kinds of energy: one a single sustained event whose activity is all in the frequency domain, the other a series of impacts whose activity is in time. Indian classical music builds its arousal along the time axis under an almost constant loudness—an alap at one event a second, then a jor with pulse, then a jhala at ten. A raga’s crescendo is a crescendo of events, not of decibels. Metal builds along all four axes at once and then spends the fourth to buy more of the first. ## The Nine Flavours The Sanskrit theorists had a vocabulary for the fifth thing two thousand years before the psychologists did. The Natyashastra, a treatise on drama compiled around the turn of the common era, names eight rasas—literally _juices_ or _flavours_—that a performance can produce in its audience: shringara, the erotic or loving; hasya, the comic; karuna, the pathetic; raudra, the furious; vira, the heroic; bhayanaka, the terrible; bibhatsa, the disgusting; adbhuta, the wondrous. A ninth, shanta, the peaceful, was argued in by Abhinavagupta around the year 1000. Each rests on a durable emotion, a sthayibhava, which the performance does not so much cause as awaken. > From the conjunction of determinants, consequents and transitory states, rasa arises. > > — —Bharata, Natyashastra, chapter 6 (the rasa-sutra) The precision is in that sentence. Rasa is not the emotion; it is the emotion’s savoured form, produced when an artist combines the causes of a feeling, its expressions and the states that flicker across it, for a listener prepared to receive them. Grief on stage is not grief; it is karuna, which one can relish—a theory of aesthetic distance eighteen centuries before Kant, and the reason a raga can be _sad_ without making anyone sad. The vagueness is in the mapping: the Natyashastra assigns modes to rasas, but they were the jatis of the ancient system, not the ragas of today, and no continuous line connects them. So the raga-rasa table every student learns is a convention, argued over, and no two teachers give quite the same one. Convention says Yaman, the sweet evening raga, carries shringara; that Darbari Kanada, the midnight raga of the Mughal court, carries karuna and a gravity the tradition calls gambhir; that Bhairav, the austere dawn raga of Shiva, carries peace shaded with awe; that Malkauns, five notes deep in the night, carries shanta with an undertone of the uncanny; that Des, the monsoon raga, carries longing. In the south the same convention hands the Carnatic Todi to pathos; Kalyani to the erotic and auspicious; Shankarabharanam to the heroic; Mohanam to joy; and Bhairavi—great in both systems, and in the north the raga with which concerts close—to devotion and a sorrow that has been resolved. *Figure: the-rasa-wheel — The nine rasas around a nonagon, each with the ragas convention gives it—Hindustani first, then Carnatic—and the Western mode or genre that reaches for the same flavour. Where a cell reads thin, the classical tradition rarely goes.* (drawn in the essay: https://epimystic.com/essays/the-raga-and-the-blast-beat/) The Western column of that wheel is not a stretch. Todi’s scale is the Phrygian, Bhairav’s the double harmonic, Kalyani and Yaman the Lydian, Malkauns the major pentatonic begun on its third: the scales cross the water intact, and what does not cross—the ornament, the drone, the hour, the phrase vocabulary—is the substance of the raga. And the associations are not merely local. In 1999 Balkwill and Thompson played twelve Hindustani ragas to thirty Canadian listeners who had never heard one; asked to rate the joy, sadness, anger and peace in each, they recognised the joy, the sadness and the anger reliably, the peace less so, using tempo and melodic complexity rather than anything cultural. Sixteen years later a group outside Delhi played ragas to Indian listeners as unmetered alap and as metered gat and found the two axes separating cleanly: the flattened notes tracked sadness regardless of tempo, the metre tracked arousal regardless of the notes. The raga chooses the valence. The tempo chooses the energy. ## The Note That Will Not Stand Still The reason a raga cannot be reduced to its scale is that its notes are not points. The theoretical vocabulary here is the twenty-two shrutis, the microtonal divisions of the octave that the Natyashastra derives from an experiment on two veenas, one retuned string by string against the other. Reconstructions of the twenty-two in cents give a ladder of just intervals—the fifth at 702, the major third at 386, the minor third at 316 or, a comma lower, 294—separated by steps of about 22, 70 and 90 cents; the comma is the syntonic comma of 21.5 cents, [the same discrepancy every piano hides](https://epimystic.com/essays/the-comma-that-civilization-swallowed/). Whether practice ever used them as fixed pitches is doubtful; when Arvindh Krishnaswamy tracked the pitch of Carnatic singers he found about a dozen stable intervals and, in place of the rest, gestures.[^3] The gestures are the gamakas, and they are where the rasa actually lives. The south lists ten of them, distilled from the fifteen in the thirteenth-century Sangita Ratnakara; the north has its own names—meend for the slide, andolan for the slow oscillation, kan for the grace note, gamak for the heavy shake—and a raga is defined as much by which gamaka goes on which note as by which notes are present. Todi’s third is not a pitch; it is an oscillation that begins near the second and rises. Darbari’s third and sixth are andolan notes, sung a little flatter than the ordinary flat third and sixth and set slowly swinging beneath the grid. Take the swing away and you have a scale. Put it back and you have the court of Akbar at midnight. *Figure: the-darbari-ascent — Darbari Kanada. Above, the ascent and the crooked descent, the two oscillating notes drawn as waves. Below, each note’s distance from the equal-tempered grid in cents, magnified: the fixed notes sit within a few cents of the piano; the third and sixth swing twenty beneath.* (drawn in the essay: https://epimystic.com/essays/the-raga-and-the-blast-beat/) It matters that the cents are small. Twenty cents is a fifth of a semitone, an amount most Western listeners cannot name and every Indian listener can feel, and it is the sense in which this music channels energy through frequency: not that Sa vibrates at a healing number, but that a trained voice moves a note twenty cents below its resting place, slowly, against a drone that fixes the reference to a fraction of a hertz, and the listener who knows the raga feels the floor give slightly. The blues found the same door from the other side, and [the codex has already followed it there](https://epimystic.com/essays/the-arithmetic-of-feeling-on-the-mathematics-of-music/). The north keeps one more dimension the West let go of: the hour. The convention, systematised by Bhatkhande out of much older practice, divides the day into eight watches of three hours and gives each raga its own, and the assignment follows the notes—a flat second with a natural third for the twilights, Bhairav at dawn and Marwa and Purvi at dusk; a natural second and sixth for the hours after sunrise and after dark; a flat third or seventh for the late morning and the deep night. Whether the rule describes anything in the ear, or only in the tradition, nobody has cleanly tested. But it does something the physics does not: it makes the listener arrive already tuned. ## Affect Across the Water The West has had a rasa theory of its own. Plato, in the third book of the _Republic_, keeps the Dorian and Phrygian modes for their courage and restraint and banishes the Lydian and Mixolydian as soft and mournful—a scale as a moral quantity. Zarlino in 1558 moved the affect into the interval: a major third above the bass was cheerful, a minor third sad, and the whole later story of major and minor grows from that. By the eighteenth century the German writers had a system, the Doctrine of Affections, in which a composer selected one passion for a movement and encoded it through rhythm, interval, key and figure, as a rhetorician selects a mode of persuasion; Mattheson ran through the keys one by one in 1713, assigning each its passion. The keys are the part that survived. In the unequal temperaments most keyboards had until the nineteenth century, keys genuinely differed in colour because the thirds were purer in some and rougher in others, and Schubart, writing in prison around 1784, gave each its character in a table that is still quoted. C minor was the tragic key, and Beethoven’s C minor is a case the theorists did not have to invent: the _Pathétique_, the Fifth Symphony, the third piano concerto, the _Coriolan_ overture and the last sonata share a temperature that is not in the notes alone. Equal temperament flattened the differences between keys to nothing measurable, and the associations held anyway: they had migrated from the tuning into the culture. > Declaration of love and at the same time the lament of unhappy love. > > — —C. F. D. Schubart, Ideen zu einer Ästhetik der Tonkunst, on C minor Tested, the Western system behaves like the Indian one. Kate Hevner’s experiments in the 1930s, playing the same piece in altered versions, found that tempo swung listeners’ judgements more than anything else and mode second. The finding has held for ninety years with one caveat that matters: the major-minor split is learned, since listeners from cultures without Western harmony hear it weakly or not at all, while the tempo effect crosses every border tested. Energy is universal. Flavour is a dialect. ## The Loud Country If metal did not exist, someone studying the rasa wheel would have had to predict it. Three flavours sit almost empty in the classical traditions of both hemispheres, and a music arrived in 1970, made for a listener standing in a crowd rather than seated at peace, that took them as its founding purpose. The first riff on the first Black Sabbath record moves from a G to the G an octave up and then to a D flat: a tritone, six hundred cents, exactly half an octave, the one interval that is its own inversion and points nowhere: the devil in music. Metal put it on the first beat and stayed there, and its subdivision since is a division of the energy map into territories. Doom took the slow, dark, loud corner: forty to eighty beats a minute, guitars tuned down to C or below, chords held until the amplifier’s feedback joins the harmony. Its energy is amplitude and spectral density at near-zero event rate; a doom riff is a tanpura through a Marshall stack, and its rasa is a mixture of shanta and bhayanaka nothing else quite reaches. Death metal took the fast, dense, mid-heavy corner: blast beats, tremolo-picked riffs, seven- and eight-string guitars whose lowest strings sit at sixty-two and forty-six hertz, and the growl, produced with the false vocal folds, whose spectrum is nearly noise—the voice as percussion. Its rasas are raudra and bibhatsa. Black metal took the fast, thin, bright corner, the bass deliberately absent and the treble pushed until the guitars become a hiss of harmonics; its rasa is bhayanaka, its production an engineering of the centroid. Rock, in the middle of the map, is the compromise the extremes departed from: the backbeat on two and four, a centroid near two kilohertz. Jazz built its energy from a different material. Swing is the ratio between the long and short notes of a pair, and when Friberg and Sundström measured it off the records of four famous drummers they found it was not a ratio but a clock: three and a half to one at slow tempi, sliding to one to one near three hundred beats a minute, with the short note holding near a hundred milliseconds throughout. And the extensions—the ninth, the eleventh, the thirteenth stacked on a seventh until the harmony is a cloud rather than a triad—are jazz’s version of the tanpura’s lifted harmonics: one moment made spectrally rich, so that the energy can live in colour rather than speed. > **Energy is universal. Flavour is a dialect. A blast beat and a jhala are the same sentence spoken in different accents.** ## What Is Channelled So the honest account of how music channels energy has two halves. The first is physics and physiology: a listener’s arousal follows the loudness, the event rate, the brightness and the contrast of what they hear, across every culture tested, with tempo the strongest single lever. A raga builds it along one axis over an hour; a metal band along four in a minute; a jazz drummer from a fixed hundred milliseconds. The tanpura’s grazing bridge and the amplifier’s clipped wave are the same trick, and the fact that one trick serves a court singer and a death-metal guitarist ought to make you like both of them more. The second half is the flavour, and it is not physics. The traditions that named it—rasa in the east, affect in the west—were saying that a feeling can be shaped so that it is received rather than suffered, and that the shaping is a craft with rules: this note, oscillated so, at this hour; this key, this figure, this dance. The rules are dialects, and they do not cross the water. But every dialect says the same thing: the energy is not the point. The energy is the carrier. What is channelled is a flavour of being alive, [held long enough to be tasted](https://epimystic.com/essays/music-meditation-and-the-flow-state/)—and knowing how the bridge grazes the string makes the drone more astonishing, not less. --- [^1]: Loudness is now measured in LUFS, a unit weighted to the ear’s sensitivity. The streaming services turn every track down to about minus fourteen before it reaches you, which is why a brick-walled master no longer wins anything but its own distortion; the loudness war has been quietly over since the services began normalising. [^2]: Raman’s paper (in Further reading) is the origin of the whole line of work; the modern measurements of the jvari, with the thread moved millimetre by millimetre along the bridge, confirm his account and add the slow migration of energy through the harmonics that gives the drone its shimmer. [^3]: Arvindh Krishnaswamy’s pitch-tracking studies at Stanford in 2003 and 2004 are the source for the claim that Carnatic practice uses about a dozen fixed intervals plus a repertoire of gestures; his phrase for the gestures is ‘multi-dimensional musical atoms’, which is exactly right. ## Further reading - **On Some Indian Stringed Instruments** — C. V. Raman. Five pages from 1921 in which the physicist who would win the Nobel prize nine years later explains why a tanpura breaks the Young-Helmholtz law: the curved bridge grazes the string and pours its energy up into the harmonics. The whole acoustics of the drone starts here. - **Music and Musical Thought in Early India** — Lewis Rowell. The best single account in English of what the Natyashastra and its successors actually say about rasa, the jatis that preceded the ragas, and the strange, precise vocabulary of the twenty-two shrutis—read as theory rather than as scripture. - **A History of Key Characteristics in the Eighteenth and Early Nineteenth Centuries** — Rita Steblin. Where the Schubart quotation in this essay comes from, alongside every other claim that C minor is tragic and E-flat heroic. Steblin’s argument is that unequal temperaments gave the keys genuinely different colours, and that the doctrine outlived the tunings that justified it. - **A Cross-Cultural Investigation of the Perception of Emotion in Music: Psychophysical and Cultural Cues** — Laura-Lee Balkwill and William Forde Thompson. The 1999 study in which thirty Western listeners, hearing Hindustani ragas for the first time, picked out joy, sadness and anger well above chance—and did it, the analysis shows, from tempo and melodic complexity rather than from anything they had learned. - **Emotional Responses to Hindustani Raga Music: The Role of Musical Structure** — Avantika Mathur, Suhas Vijayakumar, Bhismadev Chakrabarti and Nandini Chatterjee Singh. The 2015 paper that separated the raga from its tempo by playing each one twice, as unmetered alap and as metered gat. The flattened notes tracked sadness and tension; the metre tracked arousal. It is the cleanest evidence yet that the two axes of feeling in music are carried by different things. - **Swing Ratios and Ensemble Timing in Jazz Performance: Evidence for a Common Rhythmic Pattern** — Anders Friberg and Andreas Sundström. Four famous drummers measured off their records: the swing ratio slides from about 3.5 to 1 at slow tempi down to 1 to 1 at three hundred beats a minute, with the short note holding near a tenth of a second throughout. Swing, it turns out, is a constant in time rather than a ratio.