whats the difference between trumpet and piano sheet music?

Best way to find free sheet music is with a search with the song title, "sheet music" and "free" in the search bar. It's unlikely you'll find trumpet sheet music for any pop music, so piano will probably be the closest you'll get.

And as for the piano vs. trumpet sheet music: the top line of the piano sheet music likely is the vocal line and is what your son should play, so piano sheet music will work fine.

guitar notation is written an octave above the pitch that the guitar actually plays. It's written on 1 staff I believe, It's been a long time since I've used musical notation, I usually just learn by ear. A lot of guitar sheet music will be written in tablature, which is a lot easier to understand for the guitar because it's logical and functional, rather than musical notation that will cause confusion because most notes on the guitar can be played in more than one place. tablature also provides a means whereby you can represent things like bends, vibrato, upstrokes, downstrokes etc, which musical notation does not. the best way is to be able to play nearly anything by ear (the only thing I can't play by ear on the guitar/bass guitar is the really fast solos because my brain cant process where the notes are fast enough), that way you don't need to buy expensive sheet music. using headphones is a good way to do this because you can hear things in music that may get buried when you listen through speakers.

You can download sheet music for trumpet at the Trumpet Sheet Music site ( http://download-sheet-music-online.com/trumpet.htm... ).