When the band director calls out a concert pitch, every section plays a different written note. This chart answers it for every instrument: pick a concert note and your instrument to see the note to play, or flip the direction to find the concert pitch of a note in your part. Concert B♭ is a written C on clarinet, trumpet and tenor sax, a G on alto and bari sax, and an F on French horn.
Below the calculator, the full chart lists all twelve notes for C, B♭, E♭ and F instruments, and the scale table shows which major scale to play when the band warms up on a concert key, with the key signature for each. Every result spells notes the way they appear in band music, with flats where the parts use flats.