Practice Band

Why it is built this way

The choices behind the line ideas, so you can apply the same logic on your own.

1. Substitutes a third away. Chords a third apart share three of their four notes, so they do the same job: I, iii and vi are tonic, ii and IV are subdominant, V and vii are dominant. That is why one arpeggio can stand in for another without the harmony changing.
2. In the blues the substitute is a m7♭5. In a major key the arpeggio from the 3rd of Cmaj7 is Em7. In a blues almost every chord is a dominant, and the arpeggio from the 3rd of a dominant is a m7♭5 (Am7♭5 over F7). Same rule, different shape. On Gm7 it goes back to a maj7 (B♭maj7).
3. Every line starts on the 3rd. The 3rd is the note that says which chord it is. If it lands on beat 1, anyone can hear the changes in your line, even with no comping behind you.
4. The last eighth note is a half step below the next 3rd. This is how bebop connects chords: the line reaches the next chord by a half step, so the change lands on beat 1 instead of a beat late. It is shown in orange with an arrow.
5. The bebop scale has one extra note. A normal scale has seven notes and a bar has eight eighth notes, so the chord tones end up on the weak beats. The chromatic note between the root and the ♭7 fixes that: 3, root, ♭7 and 5 fall on the beats.
6. "Think minor" is there as a contrast. The minor 7 a fifth above has no 3rd of the dominant, so it floats instead of pulling. It is there so you hear the difference between tension and color, not because it is better.
7. The tritone sub only appears when the chord resolves. G♭7 works over C7 because they share the tritone (E and B♭), but only when C7 is going to F. On chords that don't resolve down a fifth the line falls back to "3 to 9".
8. Enclosures: a whole step above, a half step below. The half step below is the strongest pull into a note. The note above keeps the line from sounding like a chromatic exercise.
9. Notes are spelled by degree. The 3rd of D7 is F♯, not G♭, even in a flat key. That way the name matches the function. The one exception is notes that would come out as C♭ or F♭, which are written B and E.
10. The tab stays in position. The line stays between the G below middle C and the E on the 12th fret of the high E string, the middle of the neck, where a jazz guitar sounds round. For each chord the tab picks one hand position (the "pos" number, mostly between 5 and 9) and only moves when the notes require it. A note that comes back in the same bar is played in the same spot. That is how jazz players think: across the strings, not up and down one.
11. The same line every chorus. The lead guitar is a model to copy, not a soloist. It repeats on purpose so you can learn it, then turn it down and play it yourself.
12. Accents on the "and". The offbeat eighths are a little louder than the downbeats, and the swing gets straighter as the tempo rises. That is how bebop lines are phrased.
13. "Compose another line" keeps the rules. Each new line is drawn at random, but only from moves that follow the idea: where the arpeggio starts (3rd, 9th, 5th, root), which direction it goes, a skip in the order, or an eighth rest to breathe. The 3rd on beat 1 and the half step into the next chord stay. "Composer" goes further and picks a different idea for each chord, which is closer to how a real solo mixes devices.
14. "Chet style" comes from your transcriptions. Reading I Fall In Love Too Easily, But Not For Me, My Ideal, Just Friends, There Will Never Be Another You and It Could Happen To You, the pattern is: a melodic eighth-note phrase of one or two bars, a long note at the end, very often tied across the beat or the bar line (he anticipates the next chord), then two or three beats of rest. Entrances are on the "and". The lines walk down by step with chromatic passing notes (B♭ A A♭ G), small turns around a note and repeated notes; sometimes an arpeggio up and a scale down. A rhythm often comes back in the next phrase. The long notes follow your notes on his style: they move as little as possible from chord to chord (a major 3rd becoming minor, a maj7 becoming ♭7), and over a V that resolves he sometimes plays the tonic triad, which sounds as 9, 11 and 13. The tilde (~) means keep holding, also across the bar line.
15. "It's Always You" added the ornaments. On Chet Baker Sings he fills the ii-V-iii-VI changes with eighth-note triplets, quick runs of sixteenths that dip into the low register and come back up an arpeggio, and a grace note a half step below a target. Many phrases land short on beat 1 of the iii chord (often the same note repeated, as an anticipation) and then rest for half a bar. Those figures are in the line, more at ballad tempos and none above 200, and the tune's changes are in the tune list so you can practice them where he played them.
16. How High the Moon and Summertime added repetition and silence. Over Bm7 B♭7 | Am7 D7, played twice, he plays the very same phrase twice: when the changes repeat, the line repeats its phrase about half the time. Some phrases are just quarter notes with repeated notes, close to singing the melody, and in Summertime he lays out for a bar or two several times. The line does the same.
17. Chasing the Bird, Blue Room and the But Not For Me intro added rhythm and sequences. In Chasing the Bird (Live in Paris) the eighths are detached, with rests inside the phrase. In the But Not For Me intro (Chet Sings) a phrase comes back with the same rhythm and shape a step lower over the next chords: a sequence, adjusted so the notes fit the new chord. Blue Room (The Touch of Your Lips) is built on dotted quarter plus eighth, holds a note for more than a bar, and enters the long note with a triplet. All of that is in the line now.
18. Other tunes, same logic. The minor blues, Autumn Leaves, rhythm changes and the ii-V-I loop add two chord types the blues doesn't have: maj7 (the arpeggio from its 3rd is a m7: Em7 over Cmaj7 gives Cmaj9) and m7♭5 (from its 3rd you get a m(maj7): Fm(maj7) over Dm7♭5). Every idea works on them without changing the rules.
19. Trading 2s. Two bars of the model, two of yours. You answer with the same idea right after hearing it, which is how it sticks, and it is how a jam session works.