Find Beats with Both Voices

Supplied materials

• Paper and a pencil, or typed notes. Draw a labeled beat grid for voices A and B.
• Example: Voice A sounds on labeled beats 1–9. Voice B joins on beat 2 and both stop after beat 9. How many labeled beats contain both voices? Choices: (A) 10 beats (B) 7 beats (C) 8 beats (D) 9 beats.
• Try this: Voice A sounds on beats 1–5; voice B joins on beat 3 and both stop after beat 5. On how many beats do both voices sound? Choices: (A) 2 beats (B) 3 beats (C) 4 beats (D) 5 beats.

Learn the idea

A layered score plans two parts at once. To count the labeled beats they share, start at the second voice’s first beat and include the common last beat.

Look at the example. The shared labels are 2, 3, 4, 5, 6, 7, 8, 9. Including both endpoint labels gives 9−2+1=8 simultaneously scheduled positions. This count includes every shared beat label. It counts positions in the plan.

These questions count beat labels, including both endpoints. Finding elapsed time between two times is a different calculation.

1. Read the example’s start and stop beats. List every beat label where both A and B sound.
2. Compare counting labels 2 through 9 with subtracting 2 from 9. Explain why including both endpoint labels gives eight beats.
3. Try the check question and the three practice questions. Then read the feedback.
4. Make a six-beat grid with A on beats one through six and B on beats three through six.
5. Check your work. Shared positions are three, four, five and six, giving four simultaneously sounding labeled beats.

Check your reasoning

Your answer is temporary and is not saved to an account. Download your current answer before leaving or reloading. Written work on paper or in another app stays in your own file.

Take it further

Try a new example: Voice A sounds on labeled beats 1–8. Voice B joins on beat 4 and both stop after beat 8. How many labeled beats carry both parts? Choices: (A) 4 beats (B) 5 beats (C) 6 beats (D) 7 beats. Answer: 5 beats. The shared beat labels are 4, 5, 6, 7, 8. Count both endpoints: 8−4+1=5 positions. These are labeled beat positions in the plan. Count both endpoints. Make your own: Make a six-beat grid with A on beats one through six and B on beats three through six. Check your work: Shared positions are three, four, five and six, giving four simultaneously sounding labeled beats.

Nothing here is saved to an account or sent to a teacher. The answer download includes your current choice and any checked feedback. It does not include choices from the separate More practice section. Download that section separately.