Although this is a solo guitar piece, I wouldn’t be surprised if Joe Satriani wrote “Tears in the Rain” on piano as I found it much easier to play on piano despite still being a beginner. Plus, the guitar part has some big stretches for the right hand, which probably aren’t a problem for Joe at all, so maybe he did write it on one of his guitars. I don’t know; I’m just typing my random thoughts.
Drats, I messed the guitar part up a little – I recorded the piano part first and that took quite a few takes, so by the time I sat down to record the guitar part, I just couldn’t be bothered with multiple takes. I was all multi-taked out.