Random sound playback - how?

Hi, Is it possible to design / write something that will achieve the following?

Audio playback from MacBook via 3.5mm jack to the Arduino and then for the Arduino to produce random audio playback.

I'm thinking of a few short 0.5sec to 1sec bursts or single pulse and up to a period of 90secs to a max of few minutes. For the playback periods to be random but not greater than the maximum time period set.

Is this possible and how would I go about designing this?

Set iTunes to "shuffle" and forget about the Arduino...

I'm thinking of a few short 0.5sec

Which is more that the storage an Arduino Uno has.

You will have to store any audio input in an SD card, and then play it. Ack from that. Why do you want to do such a thing?