Bdim is a diminished, spelled B, D and F. In Drop D tuning (D2 A2 D3 G3 B3 E4) the easiest shape is x2343x, which sits at fret 2, spans 2 frets and mutes 2 strings. 12 positions for it are shown below, from the nut up to fret 14.
Notes and intervals
Note
B
D
F
Interval
1P
3m
5d
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.
x2343xsits at fret 2, spans 2 frets and mutes 2 stringsx20401sits at fret 1, spans 3 frets, lets 2 strings ring open and mutes 1 string98010010sits at fret 8, spans 2 frets and lets 2 strings ring open98070xsits at fret 7, spans 2 frets, lets 2 strings ring open and mutes 1 string05340xsits at fret 3, spans 2 frets, lets 2 strings ring open and mutes 1 stringxx910010sits at fret 9, spans 1 fret, lets 1 string ring open and mutes 2 strings05040xsits at fret 4, spans 1 fret, lets 3 strings ring open and mutes 1 string050767sits at fret 5, spans 2 frets and lets 2 strings ring open080767sits at fret 6, spans 2 frets and lets 2 strings ring openxx0100xsits at fret 10, needs no stretch at all, lets 2 strings ring open and mutes 3 strings01415xxxsits at fret 14, spans 1 fret, lets 1 string ring open and mutes 3 strings01412xxxsits at fret 12, spans 2 frets, lets 1 string ring open and mutes 3 strings
Keys Bdim belongs to
Bdim is diatonic to 8 of the 96 keys this app knows, playing a different role in each.