Some guitarists choose open tunings that use more complex chords, which gives them more available intervals on the open strings. C6, E6, E7, E6/9 and other such tunings are common among lap-steel players such as Hawaiian slack-key guitarists and country guitarists, and are also sometimes applied to the regular guitar by bottleneck players striving to emulate these styles. A common C6 tuning, for example, is C–E–G–A–C–E, which provides open major and minor thirds, open major and minor sixths, fifths, and octaves. By contrast, most open major or open minor tunings provide only octaves, fifths, and either a major third/sixth or a minor third/sixth—but not both. Don Helms of Hank Williams band favored C6 tuning; slack-key artist Henry Kaleialoha Allen uses a modified C6/7 (C6 tuning with a B♭ on the bottom); Harmon Davis favored E7 tuning; David Gilmour has used an open G6 tuning.