Fb is a major, spelled Fb, Ab and Cb. In Open G tuning (D2 G2 D3 G3 B3 D4) the easiest shape is 212102, which sits at fret 1, needs a barre across 3 strings at fret 1 and lets 1 string ring open. 12 positions for it are shown below, from the nut up to fret 13.
Notes and intervals
Note
Fb
Ab
Cb
Interval
1P
3M
5P
12 ways to play it
Ordered by how hard they are to fret, easiest first, one per position on the neck. Fret numbers are relative to the position marked beside each grid.
212102sits at fret 1, needs a barre across 3 strings at fret 1 and lets 1 string ring openx99999sits at fret 9, needs a barre across 5 strings at fret 9 and mutes 1 stringx96909sits at fret 6, spans 3 frets, lets 1 string ring open and mutes 1 string14131413014sits at fret 13, needs a barre across 3 strings at fret 13 and lets 1 string ring openx46456sits at fret 4, needs a barre across 3 strings at fret 4 and mutes 1 string242406sits at fret 2, needs a barre across 3 strings at fret 2 and lets 1 string ring openxx14131214sits at fret 12, spans 2 frets and mutes 2 stringsx9695xsits at fret 5, spans 4 frets and mutes 2 strings21210xsits at fret 1, needs a barre across 3 strings at fret 1, lets 1 string ring open and mutes 1 stringxx2102sits at fret 1, spans 1 fret, lets 1 string ring open and mutes 2 stringsxx210xsits at fret 1, spans 1 fret, lets 1 string ring open and mutes 3 stringsx12102sits at fret 1, needs a barre across 3 strings at fret 1, lets 1 string ring open and mutes 1 string
Keys Fb belongs to
Fb is diatonic to 24 of the 96 keys this app knows, playing a different role in each.