// Level tags + the two intermediate progressions added by task P-20.
// Intermediate-entry theory verified against: musictheorymanual.com &
// learnjazzstandards.com (Girl from Ipanema tritone sub, ii–♭II7–I),
// pianogroove.com (Ipanema harmony/comping analysis), Wikipedia: Rhythm changes
// (bridge = III7–VI7–II7–V7 circle of dominants), docs/progression-repertoire.md §1.
export default [
  {
    id: 'jazz-251-major',
    name: 'ii–V–I',
    rn: ['ii7', 'V7', 'Imaj7'],
    degrees: [2, 7, 0],
    qualities: ['min7', 'dom7', 'maj7'],
    bars: [1, 1, 2],
    mode: 'major',
    songs: ['All The Things You Are', 'Tune Up — Miles Davis', 'Honeysuckle Rose'],
    tip: 'The 7th of each chord resolves down a half-step to the 3rd of the next — that two-note thread is the whole progression.',
    level: 'foundation',
  },
  {
    id: 'jazz-251-minor',
    name: 'minor ii–V–i',
    rn: ['iiø7', 'V7', 'i7'],
    degrees: [2, 7, 0],
    qualities: ['half_dim', 'dom7', 'min7'],
    bars: [1, 1, 2],
    mode: 'minor',
    songs: ['Autumn Leaves (bridge)', 'Blue Bossa', 'Beautiful Love'],
    tip: 'Same engine as the major ii–V–I, darker fuel: the ♭5 of the iiø7 is the ♭9 colour waiting to happen on the V7.',
    level: 'foundation',
  },
  {
    id: 'jazz-rhythm-a',
    name: 'Rhythm changes turnaround',
    rn: ['Imaj7', 'vi7', 'ii7', 'V7'],
    degrees: [0, 9, 2, 7],
    qualities: ['maj7', 'min7', 'min7', 'dom7'],
    bars: [1, 1, 1, 1],
    mode: 'major',
    songs: ['I Got Rhythm — Gershwin', 'Oleo — Sonny Rollins', 'Blue Moon'],
    tip: 'A loop, not a line — bar 4 hands you straight back to bar 1. Learn it as one circular shape your hands repeat.',
    level: 'foundation',
  },
  {
    id: 'jazz-625',
    name: 'vi–ii–V–I circle',
    rn: ['vi7', 'ii7', 'V7', 'Imaj7'],
    degrees: [9, 2, 7, 0],
    qualities: ['min7', 'min7', 'dom7', 'maj7'],
    bars: [1, 1, 1, 1],
    mode: 'major',
    songs: ['Fly Me to the Moon', 'Autumn Leaves (A section, relative view)'],
    tip: 'Pure circle-of-fifths motion: every root falls a fifth. If you can hear this one, you can predict half the jazz repertoire.',
    level: 'foundation',
  },
  {
    id: 'jazz-blues',
    name: 'Jazz blues (12-bar)',
    rn: ['I7', 'IV7', 'I7', 'I7', 'IV7', 'IV7', 'I7', 'VI7', 'ii7', 'V7', 'I7', 'V7'],
    degrees: [0, 5, 0, 0, 5, 5, 0, 9, 2, 7, 0, 7],
    qualities: ['dom7', 'dom7', 'dom7', 'dom7', 'dom7', 'dom7', 'dom7', 'dom7', 'min7', 'dom7', 'dom7', 'dom7'],
    bars: [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
    mode: 'major',
    songs: ["Billie's Bounce — Charlie Parker", "Now's the Time — Charlie Parker", 'Tenor Madness — Sonny Rollins'],
    tip: 'A 12-bar blues wearing a suit: bars 8-10 swap the plain V-IV for a VI7 → ii–V turnaround. Hear bar 8 coming and you sound like a jazz player.',
    level: 'foundation',
  },
  {
    id: 'jazz-tritone-sub',
    name: 'Tritone-sub cadence (ii–♭II7–I)',
    rn: ['ii7', '♭II7', 'Imaj7'],
    degrees: [2, 1, 0],
    qualities: ['min7', 'dom7', 'maj7'],
    bars: [1, 1, 2],
    mode: 'major',
    songs: ['The Girl from Ipanema — Jobim (ii–♭II7–I in the A section)', 'standard substitute for any V7 in any tune'],
    tip: 'The ♭II7 replaces V7 because they share the same tritone — the 3rd and ♭7 simply trade names. What changes is the bass: 2–♭2–1, a chromatic slide instead of a fifth-fall. Your old ii–V line still works over it.',
    level: 'intermediate',
  },
  {
    id: 'jazz-rhythm-bridge',
    name: 'Rhythm changes bridge (circle of dominants)',
    rn: ['III7', 'VI7', 'II7', 'V7'],
    degrees: [4, 9, 2, 7],
    qualities: ['dom7', 'dom7', 'dom7', 'dom7'],
    bars: [2, 2, 2, 2],
    mode: 'major',
    songs: ['I Got Rhythm — Gershwin (bridge)', 'Oleo — Sonny Rollins (bridge)', 'Anthropology — Parker/Gillespie (bridge)'],
    tip: 'Four dominants, each the V of the next — the bridge leaves home and falls back in fifths until it hands you the A section. Follow the ♭7 of each chord dropping a half step onto the 3rd of the next; that chromatic thread is your solo map.',
    level: 'intermediate',
  },
]