I played mandolin for many years, trying to get fast enough to play convincing bluegrass, but never really did. I like Celtic better anyway so that's what I played mostly. Celtic is much more based on playing the melody than improvisation over chord changes, whereas improvs/solos in bluegrass are typical. So I didn't spend much time trying to improvise. Then I set the mando down for a few years. In the meantime I played a lot of guitar and got quite a bit better at improvising and being able to put my fingers in the right place to play the note I was thinking about (as compared to randomly playing scales/box patterns, my phrases now actually tend to end on a tonic note). So yesterday I got out my electric mandolin and realized I can improvise on that much better than I could before, even though I haven't been playing it. Certainly I had the scale patterns memorized already, but I seem to have made a quantum leap in improvisational skill without having played the instrument very much. Earlier this summer I took a little MIDI keyboard on vacation to mess around with and in spite of really having very few skills on keyboard at all, I found that I could peck out melodies and improvise stuff there way better than I used to as well. I was pretty surprised.. "Way better than I used to" is still pretty bad, but heading in the right direction. Interested in hearing other people's experiences along these lines.