Computer? There are SOOO many unique sounds that just can not be made using live instrumentation. You need a computer for at least some part of most music anyway.

That shit is not easy though. Not just anybody can make a beat using a computer (I mean a usable beat). You need some knowledge, creativity, experience, love/knowledge of music...talking about notes, bars, different parts of the song, choruses, first/second/third 16, intro, outro, bridges...snares, hi-hats, bassline, melody, piano roll, you gotta mix it, smooth it out, put everything in place...shit without a computer these days, there wouldn't be the quality of music that we see these days.