Originally Answered: How do you convert piano sheet music into trumpet sheet music?
Piano music is in the key of C, and your trumpet is in Bb. Thus, you need to raise the pitch of your instrument to make it sound in the same key as the piano. So you take the note that is on the piano and raise it one whole step (two half steps.)
But it gets a little bit more complicated than that. First, take all of the notes on the piano music and raise them one line/space above. If it is on a line, move it to the space right above it. If it is on a space, move it to the line right above it. As for the key signature, you need to add two sharps (#) or in other words, subtract two flats (b.) Simply take they key it is in and move it around the circle of fourths (in the image below) two keys to the right. That will give you the new key signature that you need to play in. Then copy any accidentals from the original piece into your new key.
You can play it as written in the original piece and it will sound fine when you play it alone. However, if you want to play with other instruments you need to transpose it.