Figured I'd contribute something.... Not sure if any of the sounds I've made are really that complicated, but some of them might be interesting if you're a beginner I guess.
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Pads @ 1:36 -> 2:30
I used fruity loops for this, no reason why you couldn't do it with something else, but I worked with the 3xosc, for those of you who don't know what it is it does what it says on the tin really. 3 oscillators each an octave apart from the last, which you can set to a few varied settings, sine/saw/square/ramp or a sort of half square half saw wave thing or white noise - I think those are all the options. It's pretty basic but easy to quick to use. you don't really have to use the 3xosc, you can mess around with more complicated synth set ups to get a similar or probably better effect.
Open a 3xosc, leave it as sine waves, write a short 4 chord sequence that will work when it's played backwards, make all the notes legato slide to each other to get that weird liquidy feel out of it.
Open another 3xosc, program in the same notes, again, use that legato slide, but use detuned saw waves, cut the low end - all you want is the high-mid/high end grit. Send both of the 3xosc to the same channel, apply a small amount of chorus and maybe put a flanger on it to make it sound a little more wet and juicy.
Open up yet another 3xoc, again, program the same notes in, set it to square waves, don't detune it, send it to a new channel and filter out the low end and the high end, should sound kinda like when you listen to music on a bad 80s radio, it's missing a lot, but it sounds pretty smooth, add a little chorus.
Sine wave 3xosc should be the loudest of the three, the saws are just to add high end color so they should be pretty quiet, the square wave osc should be in the middle somewhere.
Now export it as a wav, bring it back in, process it a little more if it needs it, then reverse the entire thing.
Write some simple piano riffs, plaster them in delay and reverb, then export, bring it back in, reverse it, and layer it in. Do the same with lots of other instruments that have a sparkly high end to them.
'Snare' Sound Layer a shit load of claps over each other, but don't let them all hit at the same time, have some of them hit slightly before where they're meant to (in this case the 2nd beat) and some hit slightly after where they're meant to. Layer in the sound of a running tap. Layer in lots of junk sounds from the EGOLESS sample pack (I highly recommend it)
4 minute mark onwards = Paul's Extreme Time Stretch. Great tool. I use it to slightly better effect in this track, where it kicks in around the
1.17 mark:
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Hopefully some of that is useful to somebody.