Pale crag martin to do so, it would cast doubts on their specific distinctness. There are several subspecies differing in plumage shade or size, although the differences are clinal, and races interbreed where their ranges meet. The pale crag martin of the nominate subspecies "P. o. obsoleta" is 12–13 cm (4.7–5.1 in) long with light brown upperparts, becoming paler on the lower back, and a short square tail that has small white patches near the tips of all but the central and outermost pairs of feathers. It has a pale grey throat, upper breast and underwing coverts, and the rest of the underparts
A Whiter Shade of Pale is also referred to humorously in the 1982 play "The Real Thing" by Tom Stoppard and in the 1991 film "The Commitments". Other writers have noted similar “family resemblances” to other works by Bach: the Sinfonia which opens the cantata "Ich steh mit einem Fuß im Grabe", BWV 156, the organ chorale Prelude "O Mensch, bewein' dein' Sünde groß" (O Man, Lament Your Sin So Great), BWV 622, from the "Orgelbüchlein" (Little Organ Book) and the Cantata "Sleepers Wake", BWV140. The music also borrows ideas from "When a Man Loves a Woman" by Percy Sledge. Procol Harum recorded "A Whiter