Some say that the first piece of true atonal music was Messiaens Mode de valeurs et d'intensités, thinking of atonal as a complete lack of tonality isn't beneficial though. This quote from National_Anthem sums it pretty well.

Atonality is really just an evolution of the kinds of tonal ambiguities you find in Berlioz, Wagner, Mahler etc. It can be thought of as extreme chromaticism where keys/tonal centres only exist for a couple of notes before there's another modulation, or as something belonging to two or more keys at the same time. It's also worth noting that the absence of a key does not constitute the absence of a tonal centre. The kinds of relations between pitches that imply tonality can still be found in a lot of atonal music, particularly that which follows more in the tradition of Schoenberg/Bartok. I'd much rather that atonal music was thought of as being without a clear sense of tonality than the absence of tonality.
Griff pretty much got it exactly. Some sections of atonal music do pertain to tonal centers, so depending upon their combinations your going to hear some tones that pull a certain way, but this is usually extremely brief and is often broken by the modulation/chromaticism that follows.

Like, if you made a 12 tone matrix and the tones of the C major scale were first, you could first have something like CDEFGAB, which wants to pull to C again, but to make it atonal, you need to add the other accidentals, C#, D#, F#, G#, and A#. Likewise, those tones in succession could seem to pull to B major, but for the overall scope of those 12 notes its atonal.

And as such, you can find tonal centers in this style of music, but they do not last. Also, they are sometimes ambiguous due to the shared notes in keys, so you can't claim its one key or the other, and that notion is often gone shortly after due to the Modulation/chromaticism.
Last edited by Life Is Brutal at Oct 29, 2011,
Not really. Ron Jarzombek has incorporated tone rows into his playing, nobody else comes to mind though. There are definitely a few out there that I'm not thinking of, but it's quite uncommon.
Woodstock Jam from the album Time Machine - Joe Satriani. All 16:07 of it.
Last edited by mdc at Oct 30, 2011,
I play a lot of atonal music/lines. One of the quickest ways to play free or atonal is over a minor, a straight minor triad (NOT a m7 chord) is to create lines using every note except the M3 and the b9 notes.

Just because it atonal does not mean it can't be melodic. I suggest checking out Carmen or the Theme to The Elephant Man. Or try out some Raymond Scott music, that guy can lose the underlying harmony and you'd never know it.