All the new noise explained.

What is spectralism? Um, wow, it's …

OK, imagine this: A composer pores over computer images of spectra, the acoustic waveforms that give sounds their colors. For example, the sounds of each vowel, A E I O U, arise from the distinctive spectra of each. A sitar has a different spectrum than a banjo, which is how we tell one from the other. A computer can turn those spectra into a visual representation. Using computer analysis, the composer can then shape pieces around the unfolding of tone colors in a sort of, um, you know … scientific way or whatever. The two recognized godfathers of spectralism are both French: Tristan Murail, now teaching at Columbia, and Gérard Grisey, who died in 1998. Here's the beginning of Grisey's Partiels.

All this, once again, is nothing entirely new. Spectralists trace their ancestry back to the intoxicating perfumes of Debussy's harmony, via the livid colors of Varèse through Stockhausen, a pioneer in electronic music who called himself a "tone-color composer." But until spectralists with their charts and computer models there was no real method of tone-color composition.

Our composer poring over computer images is a bit the cliché of spectralists, but it happens. Thus spectralism has the frisson of the trendy and cool yet technical that so much appeals to university tenure committees. But the early spectralists like Murail and Grisey did not use computers much; they did it by ear and instinct. Boston composer Joshua Fineberg, who studied with Murail, says this music is in part a reaction against the avant-garde of the '60s and '70s, and its often private, inaudible arcana: "Pieces like (Stockhausen's) Stimmung, are fundamentally static, from a harmonic perspective. … For [Grisey] it was about reestablishing …, harmonic change that was … directly perceptible." (Here's an interview with Fineberg.)

Which is to say that after Schoenberg and his fellow modernists exploded the old scales and harmonies and delved into more complex sounds, the ensuing music tended, whatever its virtues, to have a sense of drifting moment to moment without a discernable path. Spectralists want to use the kind of free harmony that composers (maybe even audiences) have gotten used to, but to imbue it with a sense of forward progress that it has rarely possessed before. Fineberg insists that the essence of spectralism is to find new ways way of achieving an old-fashioned virtue: music with an audible feeling of direction. Back to Mozart, say, but Mozart on another planet—as in say, Murail's Désintégrations.

Our other two current trends are nicely complementary, one aggressively noisy and the other aggressively pleasant. For the noisy sort, I propose the genre aesthetic brutalism. Since this music tends to have a certain punk sensibility, and authentic punks aren't given to explaining themselves other than with blows to the head, let's listen to a defining example, a cut from "Eight Songs," by Jefferson Friedman. These are arrangements of pieces by the noise band Crom-Tech, played here by the Yesaroun' Duo, Eric Hewitt on baritone sax and Samuel Z. Solomon on drums:

Here we have a real colonoscopy of a piece, and I mean that in the best sense. Yes, that was a sax and drums, run through a little mixing, but played live it sounds just as invasive. The person doing the howling was the drummer, who is called upon to scream a lot. Aesthetic brutalism is not so much in the gestures as in the frame of mind. I once went to a lecture by a young academic brutalist. It consisted of incomprehensible mathematical jargon illustrated by slides of cigarette butts on the street.

Aesthetic brutalism actually has a long ancestry. One precedent is Iannis Xenakis, the leading Greek avant-gardist of the 1950s through the '70s. Here's Xenakis' solo percussion piece Psappha, which features earsplitting explosions on a bass drum. In this piece the composer does not aspire to move you; he wants to hurt you.

In fact, Xenakis is often cited as a forerunner of spectralism, because he was much involved in new sounds—mainly sounds of the loud and hairy variety. There is a general overlap between spectralism and brutalism; the difference is mainly in sensibility. Xenakis was highly individual but still within the orbit of the midcentury European avant-garde, the generation of Stockhausen, Ligeti, and Boulez. Brutalists often have a background in heavy metal or punk and an often ahistorical sensibility formed in a riotous milieu.

The pop/ classical circuit is nothing new, either. As of 50 years ago a number of high-modernist classical composers came out of a jazz background. Among them was Mel Powell, who once played piano in the Glenn Miller Band. As a rough guess, more than half of current new-music composers started in rock. The most unreconstructed, ultra-academic 12-tone composer I know used to play lead guitar with a band called the Ohio Express, * who were leaders of the '60s "bubblegum" genre and whose hits include the immortal "Yummy Yummy Yummy I've Got Love in My Tummy."