Is the Zip-drive really fast enough?

Dear all,

A generous person in our church has donated to us a Roland SP-808 for use in our little CD editing desk. What I wish to do is pretty simple: record into the machine(sample?) songs by our choir, each about 4-5 minutes in length, then play them out, adding commentary in between each song, to an MD recorder. I would also like to 'mix' 2 songs together, that is, start the second one before the first is finished. However, I'm not sure the Zip-Drive is fast enough to do this. Is it? how many tracks of previously-sampled material can you play at the same time on this machine? (or do I need to buy a hard-disk recorder for that?).

Another newbee question: what are 'phrases' they talk about in the Roland literature? (I take it these are not phrases in the biblical sense...)

Any answers and advice would greatly benefit our efforts.

Many thanks,
Father James Vereker