Transposing Instruments: Transposing instruments are musical instruments that sound different pitches than the written music. The notes they play are notated differently from how they actually sound.
Concert Pitch: Concert pitch refers to the standard tuning used by most orchestras and bands, where no transposition is needed. It allows musicians playing different instruments to read and perform from the same sheet music without needing any additional adjustments.
Clarinet: The clarinet is one example of a Bb instrument. When clarinets play their written C, it sounds like a concert Bb because of its transposition characteristics.