Using notation to represent freeform improvisation

[Jae.Thomas]

Hello,

I have a new student which is an intermediate/advanced piano player.

He is trying to figure out ways to use reaper to record and represent his creations and play them back.

The thing is, he's just kinda improvising - so there's no actual time sig, tempo, key, etc...

what would be the best way to do this?

I have to say, I am really impressed by some of the features with notation, even if it's something i really dont use.