The W.P.A. Federal Music Project of New York City announces free music instruction - register now" poster
The pattern
This still is filed under Guarantee stack.
Define
Several guarantees, each aimed at a different reason not to buy, stacked so residual risk is named and removed.
Mechanism
Risk subtraction. One clause answers what if it breaks. Another answers what if I don't like it. The stack is the argument.
Verdict
The offer is unfamiliar or expensive
Why it works
It clearly announces a highly desirable free offer in large type, while cleverly using the border of the poster to list all the specific subjects (piano, voice, violin, etc.) without cluttering the main message.
Steal this when
You have a strong central offer that applies to many different specific categories, and you want to display the variety without losing the punchiness of the main headline.