Which instrument sounds down a major sixth from written treble?

• A. Bb bass clarinet
• B. Oboe
• C. Eb alto clarinet
• D. Bb soprano sax

Answer: (C)

In music, some instruments don’t sound the pitch written on the page; they’re transposing instruments, and their written notes produce different sounding pitches. The one that sounds a major sixth lower than what’s written in treble is the alto clarinet in E-flat. That means if you write a note on the treble staff, the performer will hear the pitch a major sixth below that written note. For example, to hear a concert C, you would write A for the alto clarinet part. The other options don’t match this interval: the oboe sounds as written in treble, while the B-flat bass clarinet and B-flat soprano sax each sound a whole step (a major second) lower than written.