What are the slide positions for happy birthday on trombone?

To play "Happy Birthday" on the Trombone, you typically use the following slide positions: For the first line, use positions 4, 2, 4, and 3. The second line follows with positions 4, 2, 4, and 5. The third line involves positions 4, 2, 4, and 3, and the final line uses positions 4, 2, 4, and 5. Adjustments may vary slightly depending on the key you choose to play in.