Samuel Sebastian Wesley (1810-76) was the son of the celebrated organist and composer Samuel Wesley. Named after his father's musical idol, Johann Sebastian Bach, he began his musical education when he was admitted as a chorister of the choir of the Chapel Royal, St James's Palace, in 1817. After holding organists' posts at several London churches he was appointed to Hereford Cathedral in 1832, and embarked on a restless series of appointments at provincial cathedrals and churches: Hereford (1832-35), Exeter (1835-42), Leeds Parish Church (1842-49), Winchester (1849-65) and Gloucester (1865-76).
Not to be confused with his father, great-grandfather, or uncle, all of whom were also "Samuel Wesley"—was dubbed by one contemporary critic as "the greatest organist now living," and that was while Felix Mendelssohn was still alive . As a composer, this particular Wesley is recognized as the "greatest composer in the English cathedral tradition between Purcell and Stanford".
Despite his stature as an organist, his output for the instrument is disappointingly small, especially when compared to his more substantial production in anthems, service music, and even secular music.
The "Introduction and Fugue" was originally published in 1836 as the first number of a proposed Studio for the Organ, and was reissued (with revisions to both introduction and fugue) in 1869. The fugue is a tightly-argued movement that reflects Wesley's admiration for the music of Bach. Its descending subject is admirably conceived in that it can be combined with itself in closely-placed stretto entries, both in its original form, augmented or inverted. Wesley's tour de force is to introduce it in all four parts simultaneously shortly before the end: in its normal form in the highest voice, augmented in the alto part, inverted in the tenor part and augmented and inverted in the pedal part.