Groove Machine: teacher answer key
Public sample teacher key. Includes model answers; open the student worksheet when assigning the activity.
MU:Cr2.1.C.HSI
Using the worksheet
- Worksheet opens the questions. New questions follow each performance; misses add a reflection prompt.
- Recorded automatically: each completed new performance: four measure patterns/totals, the prediction made before Play, drift at the start of measure 4, lock-in and groove results. Replays do not add tries.
- My work offers Copy my work and Turn in a PDF. Nothing is submitted automatically. Review written reasoning separately from game success; blank responses remain visible.
- Worksheet answers and completed tries persist on this browser only. Game progress may reset on reload. Predictions are captured at launch and retained with each completed try. Do not enter identifying details.
- On shared devices, use Clear my work and tap again to confirm. The game's Start over does not clear worksheet answers. If browser storage is blocked, export before leaving.
Numbers like "#4" match the printed worksheet. Questions marked "After a miss" appear in the game only after a missed performance; on paper they are combined into one question near the end.
Level 1: Rock beat in 4/4
- Required total: 4 quarter-note beats. Quarter kick, quarter snare, quarter kick, quarter snare in every measure: totals 4; snares begin on beats 2 and 4.
- A balanced part has zero drift at every measure start. The groove star depends on drum placement, separately from correct duration.
#1. Write one measure of your pattern, including note/rest values and drum sounds. Did all four measures lock in? MU:Cr2.1.C.HSI
Accept any four nonempty measures with the exact required total and at least one sounding note. Check the recorded pattern and drift. A duration-correct part can pass without earning the groove star.
#2. Explain why each measure must have the right total, even if all four measures add up to the correct grand total. MU:Cr2.1.C.HSI
A too-long or too-short measure shifts the start of later measures. Later compensation may restore the final end time but cannot undo earlier off-grid notes.
After a miss: Choose a missed try. What happened, and which rule would guide your next change? MU:Cr2.1.C.HSI
Use the recorded settings and result, identify the relevant rule, and propose a specific revision. Do not award credit for only copying a correct input.
Level 2: Waltz in 3/4
- Required total: 3 quarter-note beats. Dotted-half kick in every measure, or quarter kick + quarter hat + quarter hat: totals 3 and begins with kick.
- A balanced part has zero drift at every measure start. The groove star depends on drum placement, separately from correct duration.
#3. Write one measure of your pattern, including note/rest values and drum sounds. Did all four measures lock in? MU:Cr2.1.C.HSI
Accept any four nonempty measures with the exact required total and at least one sounding note. Check the recorded pattern and drift. A duration-correct part can pass without earning the groove star.
#4. A four-quarter-note pattern is reused in 3/4. Predict the drift at the start of measure 4 and explain your calculation. MU:Cr2.1.C.HSI
The first three measures each have 1 extra quarter-note beat. Drift at the start of measure 4 is +3 quarter-note beats (late). At the END of four measures it is +4; do not confuse the two.
After a miss: Choose a missed try. What happened, and which rule would guide your next change? MU:Cr2.1.C.HSI
Use the recorded settings and result, identify the relevant rule, and propose a specific revision. Do not award credit for only copying a correct input.
Level 3: Jig in 6/8
- Required total: 6 eighth notes = 3 quarter-note beats. Dotted-quarter kick + dotted-quarter kick in every measure: 1.5 + 1.5 = 3 quarter-note beats, kicks on counts 1 and 4.
- A balanced part has zero drift at every measure start. The groove star depends on drum placement, separately from correct duration.
#5. Write one measure of your pattern, including note/rest values and drum sounds. Did all four measures lock in? MU:Cr2.1.C.HSI
Accept any four nonempty measures with the exact required total and at least one sounding note. Check the recorded pattern and drift. A duration-correct part can pass without earning the groove star.
#6. Both 3/4 and 6/8 contain six eighth notes. How do their groupings and strong beats differ? MU:Cr2.1.C.HSI
3/4 groups six eighths into three pairs. 6/8 groups them into two groups of three, with strong counts 1 and 4. In this game each big 6/8 beat is a dotted quarter.
After a miss: Choose a missed try. What happened, and which rule would guide your next change? MU:Cr2.1.C.HSI
Use the recorded settings and result, identify the relevant rule, and propose a specific revision. Do not award credit for only copying a correct input.
When a performance missed (#7)
Any of the After a miss answers above. Look for the rule named correctly and the specific thing that went wrong.
Wrap-up
#8. Explain with a claim, evidence from two patterns, and reasoning why equal total duration does not always mean equal rhythm. MU:Cr2.1.C.HSI
Claim: rhythm depends on how duration and accents are arranged. Evidence: two patterns with measured drift or groove differences. Reasoning: connect measure boundaries and grouping to the comparison.