waveform "drifter" http://www.youtube.com/watch?v=FcczyIq23xs (old nu skool breaks)
summer beach waveforms http://www.youtube.com/watch?v=_E6PngNyOMY (found accidentally while searching for waveform "drifter"--not bad)
bonus, not drum and bass (rather, techno-house):
repeat orchestra "springtime" http://www.youtube.com/watch?v=Z9kZtTcBv5E