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Cornell Notes — Musical Ratios (Pre‑Unit Check)
Name: ___________________   Age: 13   Date: _______________
Essential Question: How do ratios describe musical pitch?

Notes (Main column)
- Different objects produce different sounds because their physical properties (length, mass, tension, and shape) change vibration frequency; frequency = pitch.
- Ratios describe the size of one quantity compared to another (a relationship between two numbers).
- A musical ratio compares lengths or frequencies of vibrating parts; it predicts musical intervals and how notes relate.
- 2:1 is called an octave in music (one note vibrates twice as fast as the other).
- Early mathematician: Pythagoras; he investigated musical ratios using the monochord.
- Monochord: a single string stretched over a soundbox with a movable bridge and tuning peg; used to measure pitch by changing string length.

Cues / Questions (Left column)
1) According to the video, why do different objects produce different sounds? — Because length, mass, tension and shape change vibration frequency (pitch).
2) According to the video, what do ratios describe? — How one value compares to another (their relationship).
3) What does a musical ratio describe? — The relationship between string lengths or frequencies that produces intervals.
4) What is a 2:1 ratio called in music? — An octave.
5) Who was one early mathematician interested in musical ratios? What tool did he use? — Pythagoras; he used the monochord.
6) How would you describe the monochord? — A single-string instrument on a plank or soundbox with a movable bridge and tuning peg to change sounding length.

Summary / Legal Brief (ACARA v9 aligned — 150 words)
Brief of Learning Outcome: The student (age 13) shall demonstrate proficient understanding of musical ratios by identifying how physical properties create pitch, by reading and writing simple ratios, and by explaining the monochord’s function. Findings must align with ACARA v9 content descriptions for Years 7–8: waves and sound, ratio reasoning, and practical investigation. Evidence: accurate answers to pre-unit checks, labelled sketch of a monochord, and verbal explanation of 2:1 (octave) and historical context (Pythagoras and his monochord). Recommendation: proceed to guided experiments with string length adjustments and frequency observations. Judgment: Proficient. Rationale delivered succinctly: measure, calculate, confirm. Compliance: parental or teacher supervision required. Note: firm tone, warm encouragement — excellence expected and supported. Assessment tasks include short written responses, a labelled diagram, and a recorded explanation. Success criteria: accurate labels, correct ratio naming, and ability to link ratio to frequency. This outcome supports future composition and analysis and confident performance.

Teacher / Parent Notes (Proficient outcome checklist)
- Student correctly names octave for 2:1 ratio.
- Student identifies Pythagoras and the monochord.
- Student sketches and labels components of a monochord.
- Student explains how changing length changes pitch.

Sketch / Diagram Space — Draw and Label
Instructions: In the box below, sketch a simple monochord. Label: string, movable bridge, soundbox/plank, tuning peg, and resonator (if present). Then write one sentence describing how moving the bridge changes pitch.
Tuning peg Movable bridge String (vibrating length) Soundbox / plank

Space for student sketch (hand-drawn) and label: ____________________________________________________________

One‑sentence student answer (example): Moving the bridge shortens the vibrating length of the string, which raises the frequency and produces a higher pitch.

End of handout.

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