Dominant chords (e.g. E7, F9, G11, and C13) like major chords, employ the root, a major third, and perfect fifth but always contain a flat seventh like those found minor chords. Therefore a C dominant seventh or C7 would be (C-1st, E-3rd, G-5th and B♭-flat 7th). All dominant chords contain the ninth interval as well (with the dominant seventh being the obvious exception).
Dominant seventh sharp five and dominant seventh flat five chords (e.g. F7♯5 or F7+5 and F7♭5 or F7-5) occur when the fifth interval is raised or lowered respective to the annotation in a traditional dominant chord formula.
Dominant ninth chords (e.g. B9) are yielded by adding the ninth interval to the dominant seventh chord formula of root, major 3rd, perfect fifth, and flat seventh (R, M3, P5, ♭7, 9).
Dominant seventh sharp nine and dominant seventh flat nine chords (e.g. E7♯9 and E7♭9) are produced when the ninth interval is raised or lowered, respectively. The dominant seventh sharp nine chord consists of the root, major 3rd, perfect 5th, minor (flat) 7th, and sharp 9th; this is often referred to as the Jimi Hendrix chord because of its use in his music, most notably, Purple Haze.
Dominant eleventh chords follow the same formula, with the eleventh interval attached (R, M3, P5, ♭7, 9, 11). However, as discussed later in the text, the third may be omitted. This is primarily because the third and eleventh “clash” (since the eleventh is a higher octave of the fourth) and secondly, because they contain six intervals and which may make the chord too difficult or impossible to play.
Dominant thirteenth chords are constructed from the root, major third, perfect fifth, flat seventh, ninth and thirteenth intervals (R, M3, P5, ♭7, 9,13).
Altered chords also belong to the dominant family because they contain a major third and flat seventh. Altered chords are formed when another interval (such as a ♭5 or ♯4) appear in a dominant seventh chord but do not replace any of the existing intervals. Consequently, a C7♭5 would still contain the perfect fifth as well as a flat fifth (1st-C, 3rd-E, 5th-G, flat 7th-B♭, flat 5th-G♭).