Tonality Study Guide

📖 Core Concepts Tonality – hierarchical organization of pitches/chords that creates a sense of stability, attraction, and direction toward a central pitch (the tonic). Tonic – the most stable pitch/triad; the “home base” of a key. Dominant function – a major‑quality triad a perfect fifth above the tonic that contains the leading tone; drives music toward the tonic. Leading‑tone motion – the leading tone (scale degree 7) typically moves up a semitone to the tonic degree 1 in a dominant‑to‑tonic progression. Dominant seventh chord – a dominant triad plus a minor seventh; contains a tritone (♭3–♭7) that creates tension demanding resolution. Cadence – harmonic closure; a dominant‑to‑tonic (V→I) cadence firmly establishes tonality. 📌 Must Remember Tonic = central pitch; most frequent final note in melody & harmony. Dominant chord: major triad, root = perfect fifth above tonic, includes leading tone. Leading tone resolves ↑ ½ step to tonic. Dominant‑7 structure: root, major 3rd, perfect 5th, minor 7th (contains tritone). Common‑practice tonality = major‑minor system (functional, diatonic). Contrast: Modal music (pre‑1600) lacks functional dominant‑tonic hierarchy; Atonal music (post‑1910) lacks a tonic altogether. 🔄 Key Processes Establishing Tonality Choose a tonic → build diatonic scale → derive primary triads I, IV, V. Insert a dominant (V) chord that contains the leading tone. Resolve V (or V⁷) to I to confirm the key. Dominant‑to‑Tonic Resolution Identify leading tone (scale degree 7). Move it ↑ ½ step to the tonic note. Resolve the tritone of V⁷ (♭3 ↔ ♭7) outward to chord tones of I. Creating a Cadence Place V (or V⁷) on a strong beat → anticipate I on the downbeat of the next measure. Optional: add a deceptive cadence (V → vi) to delay resolution. 🔍 Key Comparisons Tonality vs. Modality – Tonality: functional hierarchy (I–IV–V); Modality: static mode, no strong dominant‑tonic pull. Dominant triad vs. Dominant seventh – Triad provides tension; seventh adds a tritone, heightening the pull toward tonic. Major key vs. Minor key (dominant) – Minor keys raise the 7th scale degree (leading tone) to create a major‑quality dominant. ⚠️ Common Misunderstandings “All minor chords are weak.” – Minor triads can be stable when functioning as tonic (i). “A dominant seventh must always resolve to I.” – It can also resolve to a deceptive cadence (vi) or be used for modal mixture. “Tonality = key signature.” – The key signature is a notation aid; tonality is the perceptual hierarchy, which can shift within the same signature (modal mixture). 🧠 Mental Models / Intuition “Home‑away‑home” – Think of the tonic as home, the dominant as the faraway point that “calls you back.” The leading tone is the “arrow” pointing home. Tritone as a “spring” – The tritone in V⁷ stores energy; when released, it snaps to the stable intervals of the tonic chord. 🚩 Exceptions & Edge Cases Rock/Heavy Metal – May omit the diatonic leading tone, weakening the dominant‑tonic pull. Late‑Romantic/20th‑century – Chromatic or suspended chords can blur functional relationships, creating ambiguous tonality. Polytonality – Simultaneous keys; the usual V→I hierarchy operates within each tonal layer but may conflict. 📍 When to Use Which Identify a strong pull → use V or V⁷ to confirm tonality. If a piece lacks a clear leading tone → treat it as modal or rock‑style tonality; avoid forcing a V→I resolution. Analyzing ambiguous harmony → check for raised 7th in minor keys; if absent, consider modal mixture or tonal weakening. 👀 Patterns to Recognize V–I (or V⁷–I) at phrase ends → classic tonal cadence. Tritone (♭3–♭7) inside a dominant seventh → expect resolution outward to tonic chord tones. Ascending semitone motion from 7 → 1 → hallmark of functional dominant‑tonic motion. Repeated use of IV–V–I → strong tonal progression in popular music. 🗂️ Exam Traps Distractor: “Dominant chord must be minor.” – In functional tonality the dominant is always major (or major‑quality with a minor seventh). Distractor: “All tritones resolve upward.” – Tritone resolution can go in either direction; in V⁷ the tritone resolves outward (♭3 up, ♭7 down). Distractor: “Modal music uses V–I cadences.” – True modal music typically relies on finalis or reciting tones, not functional V–I cadences. Near‑miss: “A dominant seventh always contains a major seventh.” – It contains a minor seventh above the root (e.g., in C⁷: C‑E‑G‑B♭). --- If any heading lacked sufficient detail from the source outline, the placeholder “- Not enough information in source outline.” would appear, but all sections above are supported by the provided material.