The highest note a trumpet can produce
There are many varieties of trumpet, and they also vary in range. In the most common case of a B♭-pitch trumpet, the highest note that can be played is said in elementary reference books to be one octave higher than the B♭ just above the middle line of the treble clef, but there are ways to produce even higher notes. This is to say that it is not a question of the highest note the trumpet can physically produce but a question of the highest note that can be played. In fact, performances by session musicians often extend in range up to an octave higher than the high B♭ more generally considered to be the instrument's highest note.