Hi, sorry about the bashing. Classical music has what comes very close to a loop ||: (notes notes notes) :|| now imagine your notes look something like this ||: (notes notes notes) :|| _ad infinitum_ So you just go on playing these four or whatever bars of your notes and never stop. That's a loop. Simple as that. Now imagine you are among twenty other musicians who all have these one-loop music sheets, and there is a conducter telling you and the others when to start, and when to stop. In Seq24 you are that conducter, and the little boxes you see that get black when you click them are the musicians. When the box is black they are playing a loop, and when it's gray they are resting. This is called 'live mode', because you are conducting the loops live, then and there. You can also produce a song by essentially 'writing down' where each musician should start and stop playing. You this in 'Song Mode', and in Seq24 you there is a little button on the bottom right to let you enter. Now you are the double sheet music composer, first you write the loops, and then you write the directions for the conducter, and hence produce a song. If you only want to produce regular sheet music with no loops, you can make a bunch of really long loops and turn them on all at once and you have regular sheet music once again. Tracker type software like Acid or FruityLoops or LMMS is similar; here the loops are not MIDI signals (sheet music and a performer) but tape recorders with digital audio already present. That's the second type of loop based music out there. Same in principle, different in technical implementation. Hope I was helpful to you. Carlo