Diki....I have almost everything I do including all my live arranger style gig songs, SMF & Mp3's all recorded on my laptop & Thumb Drive, & on my Zen Touch player...you never know what can happen and a few times thru the years it has helped me get out of a few on stage jams for sure..
I rarely use them lately & mostly play live styles unless the occasion arises...but its always a good bet to be prepared ...