Emax

The Emax and Emax II sequencer is what is known as a scratch pad sequencer. It has 
no edit functions, no quantizing, no putting patterns together in a song mode. It simply 
records incoming MIDI events in realtime and plays them back. It was primarily designed 
so that you could layout short ideas before you forget them or so that you could dump 
sequences from a proper sequencer on a computer and them playthem back through the 
Emax II using it's supermode. 

I personally have never found any real practical songwriting uses for it, but it has been 
handy on a few occasions for dumping show opening instrumentals into it and having 
someone else press start before the band comes onstage. Of course, this was back in 
the day when I used a Comodore 64 running Master Tracks Pro as my sequencer and 
there was a noticeable load time between songs which you don't want at the beginning of 
a show.