Every part the practice tab can suggest, and how it is made
Under Part in the practice tab, the app suggests a guitar part to play over the progression: rhythm guitar with fills, in the style that is playing. There are sixty-one styles and nearly a hundred parts. This page writes each one out over a progression that suits its style, says what its rhythm and its notes are made of and where the idiom comes from, and plays it — press Play on any of them; the band plays the style, the guitar plays the part.
How a part is written. On the style’s own grid — twelve slots to the bar when it swings or is in 12/8, sixteen when it is straight — as a figure with its variants (the same bar with its weight moved, taken in turn or rolled), and fills for the bar before a chord change and for the bar before more of the same chord, in a two-bar call and answer that loops whatever the chords do. Many parts also carry tails (a lick on the end of a figure bar), pickups into a change, stop-time bars where the band drops out, turnarounds for the last bar of the form, and lead lines that about a third of rolls put in the fill bars. The practice tab rolls all of this from one seed (“New fills” is a new seed). Here six bars are shown: figure, fill, variant, fill, variant, and the turnaround where the part has one.
How the notes are chosen. A part is not written in a key, a box or a scale. Every single note is an interval above the chord’s root — 0 the root, 4 the 3rd, 7 the 5th, 10 the ♭7, 12 the octave, or a negative number for a note below the root — and some are written against the next bar’s chord, which is how a fill points where the music is going: the ♭7 falling onto the IV’s 3rd, a chromatic step up under the root that is coming. At realisation each interval becomes a pitch, is snapped to a note the neck’s reading allows — the note itself if it is there, else the nearest within a tone, downward first, else it is dropped — and is placed on the nearest such note inside the position window. So the same part plays chord tones only in the Chords reading, the five notes of the box in Pentatonic, and the whole scale in Scales, and the switch above lets you see and hear the difference.
Strums are the chord the box is built on, swept low to high the way a pick does, and each one says how much of the grip it wants: the whole thing, the bottom three strings, the top three, the root alone, the 5th alone (the two notes an alternating bass goes between — the thumb of a fingerpicked part, kept to the bass strings), a power chord, or a shell (root, 3rd and 7th), sometimes with a colour tone on top or slid in from a fret below, and whether it is palm-muted. A double stop is placed the way a hand plays it: 3rds, 4ths and 5ths on adjacent strings, 6ths and octaves with a string skipped. Techniques — double stops, bends, hammer-ons, pull-offs, slides — are written into the fills where the style has them, held to the same rule (a bend only to a note the reading allows; a hammer-on only where the string has the fret), and each plays plain when it cannot be done or is switched off: a bend as the note it bent to, a hammer-on as two picked notes, a double stop as its first note, a slide as the note slid to.
Where the parts come from. Every part is written from the idiom of its style — where the weight falls, which strings carry it, which notes it leans on, how a phrase ends — and not from any recording. The players and records named under each style are the reference points for the style; none of their lines is here. A boogie figure, a chromatic walk-up, a G-run, the Charleston figure: these are the common property of the music, the way a twelve-bar form is. What would be somebody’s is a signature riff, and none is used.