When learning to read music, you have to learn about all the different clefs that instruments use. Some are used by instruments that play in an upper register, others in a lower register, but there are some other types of clef, too.
In this post, I’m going to be looking at a clef that covers the middle register called the alto clef.
What is the Alto Clef?

The alto clef is a type of clef that’s also known as the viola clef.
Despite looking like a capital letter B, the alto clef is a type of C clef as the arches of the B show where middle C is on the stave.
What Instruments Read Alto Clef?
The alto clef is very uncommon, and the main instrument that still uses it is the viola.
It’s sometimes called the viola clef as a result!
A handful of other instruments will sometimes read using the alto clef, like:
the alto trombone, the viola da gamba and the mandola.
Alto Clef Notes
Because we know which note is C, we can then work out all the other notes in the alto clef.
Going up from C, we have these notes:
And going down from C, we have these notes:
Summing up
Although very rare, it’s still very important to know about the alto clef, especially if you’re learning music theory.