By changing which loops are playing when, you create a recording that changes over time. By spending enough time mixing things up, you can create something that sounds more like a real tune rather than a modern porn soundtrack. (At least, I imagine this is how modern porn soundtracks are probably made, I actually have no clue).
Personally, I do a lot of stuff with using only parts of loops, and chopping them up. The two best recordings here, "portis" and "bitter", both feature this in different ways.
Portis (3 MB) screenshot: Note how Solo Insert Alto and Solo Alto Ballad have been chopped up--by cutting up different pieces of it I was able to get a solo with a different feel. The harmony at the end is just two tracks playing the same sample, but one of them is pitch-shifted--but by different amounts for each phrase. The "lead guitar", which plays its full version starting at 1:03, in further appearances is extremely chopped and pitch-shifted, but in this case, intended more to sound like somebody sampling and chopping up a guitar, rather than a real guitar; whereas the wah guitar at 1:37 is carefully cut to provide more variation before the full loop appears at 1:50.
Bitter (3 MB) screenshot: Where I was content to let the drums and electric piano chords repeat in long loops on Portis, on Bitter, a dance-ish song, I tried to follow an aesthetic of avoiding any really long loops (until the end); although the bass drum does repeat for a while, there are other drums at the same time. You can see in the chart the consistent "hook" of the track is to keep stopping 4/8-measure riffs a half or full measure before the end and insert something else. Look at the section from 51 to 59 for a good example of how something that looks choppy yet perhaps straightforwardly repetitive is actually carefully a lot of very carefully orchestrated variation: it occurs at 1:38 through 1:53 in the track. Also noticeable is the lead synth line from 1:53 through 2:33; the actual line just repeats without a question-and-answer motif, but by stopping the second repetition at different points in the melody (visible as small variations on the bottom row of the screenshot) I can make the phrase "say" different things. This track also features my only ever (so far) sample from somebody else's song.
Slappy (1.4 MB mp3 from an 8-bit WAV) screenshot: This was the first thing I ever "wrote" with Acid. Although it's not the greatest thing ever, I'm still fond of a lot of the detail work; for example, you can see how I carefully placed "piccolo crash"es in various specific ways, and the subtle interplay of the guitar parts from 10-16 was me discovering the things that came to fruition in the later tracks above. You can also see I experimented a lot more with key changing (the info along the bottom lines) versus just changing single parts (the -5, -7, 0, +2 on the bass from 16-18), or the brief double-time section (the 200.000, 100.000 at the bottom). Basically a lot of experimention going on.
Faster (1.5 MB mp3 from an 8-bit WAV) screenshot: Playing around here with two bass parts at once, and the tempo running the bass parts faster than they could probably be reasonably played by a human being. Not as many subtle touches; I was trying to create something that was a bit more like a song, with the nice progression of the rising guitar riff (even if I couldn't make it harmonically adjust, it has to keep modulating up, it basically works), although the ending chromatic stuff is less effective.
Noise (0.5 MB Real Audio file) screenshot: Another experiment, this time with mostly non-musical non-drum tracks; the basic drum track, "chaos", is not very drum like, and mostly you just odd, semi-ominous, deep rumbling sorts of sounds coming in and out. Low quality because I can't find the originals, although I do still have the raw Acid files so if I reinstall Acid I can re-render it.
