F#7b5

F#7b5 is F#, A#, C and E, a seven flat five. The shape this page opens on is written 2x231x, lowest string first.

Note by note. F# is the root, A# is the major third, C is the flat fifth and E is the flat seventh.

Also written F#7(b5), F#7-5 or F#7♭5. The same chord either way; which spelling you meet depends on who wrote the chart.

There are 7 common shapes for F#7b5 on the guitar, and 32 derived voicings in 4 families.

One note away. Change a single note of F#7b5 and you have F#maj7b5 (with one note moved), F#m7b5 (with one note moved), F#7 (with one note moved), F#aug7 (with one note moved) or F#9b5 (with one note added).

The common shapes, written lowest string first: 2x231x, xx4556, x78978, xx8978, x-9-10-9-11-0, x-9-10-9-11-9, 14-x-14-15-13-x.

Under the hand. None of the shapes for F#7b5 uses an open string, so every one of them is movable; the lowest sits at the 1st fret. 1 of the 7 needs a barre. Together they cover the neck from the 1st fret to the 15th.

Where it goes. F#7b5 is a dominant with its tension raised, so it still points at B — harder than a plain seventh does, because the altered tones sit a semitone from where they are going.

Shell. Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top. F#7b5 has 2x231x, 2125xx, x-9-x-9-11-8, 14-x-14-15-13-x, xx4358, x-9-8-9-13-x.

Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. F#7b5 has xx2312, 2323xx, x3435x, xx4556, xx8978, 8989xx, x-9-10-9-11-x, x-x-10-11-11-12.

Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. F#7b5 has 2x231x, x3x352, 6x455x, x7x576, 8x897x, x-9-x-9-11-8, 12-x-10-11-11-x, x-13-x-11-13-12.

Open string. An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful. F#7b5 has 004556, 070576, 0303xx.

Tensions. A shell of F#7b5, root, third and seventh, leaves a string free, and the tones that belong over it are the b9 (G), the 9 (G#), the #9 (G##), the b13 (D) and the 13 (D#).

What kind of chord this is. F#7b5 is an altered chord — a dominant seventh with its fifth or ninth moved. altered dominant chords on every root, and what they are for.

The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.