"Spectrum" is a song by English indie rock band Florence and the Machine from their second studio album Ceremonials (2011). It was written by lead singer Florence Welch and Paul Epworth with production being handled by Epworth. The band premiered the song during a concert at Brooklyn's Creators Project on 15 October 2011, prior to the release of the album. The album version of "Spectrum" is a downtempo orchestral pop, R&B, krautrock and disco song. The accompanying music video for the song premiered on 30 May 2012. It was directed by David LaChapelle and John Byrne.

A remix of the album version of "Spectrum", titled "Spectrum (Say My Name)", was released on 6 July 2012 by Island Records, serving as the fourth single from Ceremonials. Scottish DJ Calvin Harris remixed "Spectrum", producing the uptempo single. "Spectrum (Say My Name)" became the group's first single to peak at number one on the UK Singles Chart, selling 64,816 copies in its first week. It also reached number one in Ireland and Scotland and has peaked within the top five in Australia and New Zealand.

Florence and the Machine premiered "Spectrum" along with two other songs from the album, "Never Let Me Go" and "Heartlines", as part of their set list at Brooklyn's Creators Project on 15 October 2011, two weeks before the release of the album. Musically, "Spectrum" is a downtempo orchestral pop,R&B,krautrock and disco song with drums while backing vocals repeatedly sing "Say my name" throughout the choruses. According to the sheet music published by Universal Music Publishing Group on the website Musicnotes.com, the song is set in the key B minor. The song's beat is set in common time, and moves at a tempo of 124 beats per minute. Welch's vocals span from the note of F#3 to the note of F#5 or B5 in the Calvin Harris remix.

...
Wikipedia