[5] Speaking to the Daily Express in 2007, Harley recalled, "I started busking in the early 70's, which gave me a platform to experiment on the public with my songs.

With Neil Harrison as producer, "Sebastian" was recorded with a 50-plus piece orchestra and choir alongside the band, with orchestral arrangements by Andrew Powell.

While fans have long debated the true meaning of the song (with suggestions of influence ranging from Oscar Wilde to St. Sebastian), Harley never definitively revealed it during his lifetime.

But I do know that it has just three chords and a couple of riffs and that I had been busking it in the London subways and on Portobello Road for many months before EMI offered the lads and me, the first Cockney Rebel, a recording contract.

[15] Before its release, EMI agreed to hold the song back at the beginning of 1974 and re-issue "Sebastian" on 18 January for the third time as a UK single.

[16][17][18] "Sebastian" was released by EMI Records on 7-inch vinyl in the UK, Belgium, France, Germany, the Netherlands, Portugal, Italy, Japan, Australia and Mexico.

It was exclusive to the single, but later appeared as a bonus track on the 2004 CD re-issue of The Human Menagerie, and also on the 2012 EMI box-set compilation Cavaliers: An Anthology 1973-1974.

[25] The same recording appeared as the B-side to the band's 1975 UK hit single "Mr. Raffles (Man, It Was Mean)",[26] and as a bonus track on the first CD release of The Best Years of Our Lives in 1991.

[27][28][29][30][31][32][33][34] On its first release, New Musical Express described the song as a "wonderful record", adding, "It's a classically influenced ballad with the upper lead vocals placed, delicately, in the middle of the finest string and bass arrangement I've heard since the Titanic sank.

"[36] Record Mirror commented on the song's "concert-classical type of string sounds", "strained voice", "beautiful mood", "excellent lyrics" and "first-class production".

[40] In a 2004 review of The Human Menagerie, Geoff Barton of Classic Rock commented how the album "builds insidiously until the arrival of the fifth track, the immense and immortal 'Sebastian'".

[41] Carol Clerk of Classic Rock said in a review of the 2006 release The Cockney Rebel – A Steve Harley Anthology that "Sebastian" was a "brave first single with its choral and orchestral dramas".

[43] In a retrospective review of The Human Menagerie, Dave Thompson of AllMusic felt that both the labyrinthine "Sebastian" and loquacious "Death Trip" "possess confidence, arrogance, and a doomed, decadent madness which astounds".

He described the song as a "slowly building ballad that adds layers of orchestration and choral vocals as it lays out a gothic tale of a romantic obsession that gives way to insanity".