Play C, G, and F major scales evenly, both directions.
Recognise the whole-step / half-step pattern that defines a major scale.
A scale is a melody in eight notes.
A scale is not a punishment exercise — it is a melody of eight notes, and many famous tunes (Joy to the World, the opening of Doe a Deer) are scales lightly disguised. The major scale is defined by a fixed pattern of whole and half steps: W·W·H·W·W·W·H. Apply that pattern starting on any note and you get a major scale in that key.
The three scales you know
You have already played all three; this lesson is about feeling them as related, not as three separate finger sequences.
On your alto staff these same fingerings read as F major (one flat: Bb), C major (no sharps or flats — the alto's home key), and Bb major (two flats: Bb, Eb). The titles below name the soprano keys; the notation has been transposed a fifth lower for the alto staff.
Play: Joy to the World
The opening phrase walks straight down the C major scale — a scale you already know, presented as a melody.
When all three scales play from memory at quarter = 96, both directions, with no audible gap at the half-steps on a phone recording, move on to Lesson 17.