can i play more than once at a time on my 404

I wish the answer were more complex but...
nope

However I recommend you this video:
http://www.youtube.com/watch?v=FuA8RgHaMVQ

Guy shows how to efficiently use the subsonic effect to mute the samples while the patterns playing. Nothing really insightful, but worth seeing, as it helps to diversify your current playing pattern without recording it 78678 times in different ways

thanks bro. defiantly gonna use that