The lyrics were written by Barry Mason, and the music by Les Reed, who also contributed the title and theme of the song.

[1] Although the song is a soulful number set in triple metre, the underlying genre may be considered to be a power ballad, rising to a pitch of A4 on the final note.

Produced by Peter Sullivan, Jones' version features a big-band accompaniment set to a flamenco rhythm.

There is no explicit reference to Spain, but there are similarities to the plot of the book and opera Carmen, by French composer Georges Bizet, in which Don José stabs the eponymous Romani woman to death when she tells him she is leaving him for the bullfighter, Escamillo.

On 17 April 1999, Jones performed Delilah as part of the pre-match build-up to Wales' victory over England at Wembley Stadium in the 1999 Five Nations Championship.

[38] The Welsh Rugby Union regularly played the song at the Millennium Stadium before international matches, often displaying the lyrics on large screens.

On 20 June 2003, Senedd Member Helen Mary Jones publicly raised concerns that the song "glorifies violence against women".

Iwan noted that choirs and fans inside the stadium would sing Delilah alongside his own folk song, "Yma o Hyd", and the Christian hymns "Cwm Rhondda" and "Calon Lân".

[40] Iwan's article stated that while he had written "Yma o Hyd" about the historic survival of the Welsh nation against the odds, Delilah was "a song about murder and it does tend to trivialise the idea of murdering a woman and it's a pity these words now have been elevated to the status of a secondary national anthem.

The Welsh Rugby Union also responded that they had condemned "violence against women" and had "taken a lead role in police campaigns to highlight and combat the issue."

[42][43] Following these responses, Iwan wrote a letter to the Guardian pointing out their error, adding that "banning songs is not something I would ever advocate.

The Union reiterated that "Delilah" was no longer included in playlists for Wales matches and that guest choirs had also been requested not to feature the song in more recent years.

"[47] The Welsh Rugby Union's actions were commended by the Chief Constable of Dyfed–Powys Police,[48] while singer Nick Cave stated: "I can't get too animated by the fact that Delilah has been banned.

In the first show, Jones addressed the crowd with an apparent approval of the WRUs stance: "Who was the man who didn’t want us to sing Delilah?