Teacher copy: This page may include teaching prompts or answer keys. Answer keys in this public library can be viewed by anyone. Give learners a clean prompt, use checks as formative evidence, and change a case locally when prior access matters.
Target/codes: preserve A A B B, change only place 2 to B in a second version A B B B, and show the switch moved earlier; AC9AMUFD01, AC9AMUFC01. Prepare:E two-version board, Practice E, two broad numbered strips.
Welcome · 3 min. Put first and second versions side by side; keep the original visible.
Model · 4 min. Replace only second-row place 2 A with B. The single boundary moves from 2→3 to 1→2; do not change pitch, event count or loudness.
Try together · 5 min. Child overlays the two versions and points to exactly one changed source card.
Child choice · 7 min. Child keeps or changes this switch placement for a fictional train-window scene or plain score and explains the intended musical difference.
Notice · 4 min. Save original, revision, changed place and reason. Do not claim a listener noticed it without a real trial.
Close · 2 min. Offer a blank palette to author tomorrow.
