Solution to 3: Faraway Music

    Use the bottom note, and move up the alphabet based on the size of the interval with the top note.

    1. A and B, 1 note above - B
    2. A and A, 0 notes above - A
    3. G and G (octave), 7 notes above - N
    4. B and C, 8 notes above - J
    5. A and A (2 octaves), 15 notes above - O

    This spells the word banjo.

    DISCLAIMER: I'm fully aware that this is not how the intervals would actually be named (1 is major 2nd, 4 is minor 9th, etc.), but it would be impossible to encode the letter A this way.

BANJO