(notes extracted from the full score as edited by John L Snyder)

The Symphonic Variations are based on an African-American song, "I'm troubled in mind." Coleridge-Tavlor had made a setting of it in his Twenty-four Negro Melodies, op. 59, composed in 1904 and published in 1905. Each of the melodies in that collection is preceded by a phrase or two of the original song, most with text. Coleridge-Taylor cites his sources for all but a few of the melodies set; this is one of the few for which a source is not given. The melody is contained in at least two of the sources he does cite. In all sources known to the editor, the melody is set in F minor and the text is that of the refrain; there are three verses, sung to the same music. These sources include the following statement, with only minor variations in punctuation:

The person who furnished this song (Mrs. Brown of
Nashville, formerly a slave) stated that she first heard it
from her old father when she was a child. After he had been
whipped he always went and sat on a certain log near his
cabin, and with the tears streaming down his cheeks, sang
this song with so much pathos that few could listen without
weeping from sympathy, and even his cruel oppressors
were not wholly unmoved.

Coleridge-Taylor states, "What Brahms has done for the Hungarian folk-music, Dvorák for the Bohemian, and Grieg for the Norwegian, I have tried to do for these Negro Melodies. The plan adopted has been almost without exception that of the Tema con Variazioni." His actual practice in the set, however, was neither so simple nor so uniform as that. While many of the settings are in fact of the theme-and-variations genre, others (for example, that of "Deep River") are more like ternary forms, the outer sections presenting statements of the melody in its entirety, and the middle section comprising a free development of motives derived from the main theme. 

The theme-and-variations settings are on the whole quite straightforward: the variations are almost always discrete, and, for the most part, employ the cantus firmus technique of variation — that is, the theme remains essentially intact and unornamented, with variation consisting in "new figurations and counterpoints." In this collection, "I'm troubled in mind" is treated to four such variations, the last of which is preceded by a dominant preparation and modified to serve as a coda; the tonality (F minor) remains constant.

Symphonic Variations on an African Air, op. 63, was composed during the fall and winter of 1905–6 and premiered on 14 June 1906 in London, at Queen's Hall, by the Philharmonic Society, Frederick Cowan conducting. Among the most familiar variation works employing this technique is, of course, Elgar's "Enigma"Variations, which premiered almost exactly seven years before the Symphonic Variations (on 19 June 1899). As Elgar had done, Coleridge-Taylor extracted a handful of distinct motives from his theme and re-worked them into a series of short pieces of vastly different characters.