Answer by taking a quote from the following article:

Starsailor are an English post-Britpop band, formed in 2000. Since its formation the band has included guitarist and vocalist James Walsh, drummer Ben Byrne, bassist James Stelfox and keyboardist Barry Westhead. The band has released five studio albums, and have scored ten Top 40 hit singles in the UK.

For their second album, Silence Is Easy, which was recorded in Los Angeles, Starsailor teamed up with Phil Spector. The collaboration came about following Spector's daughter Nicole attending one of the band's American concerts in the winter of 2002. Spector was reported to have been fascinated by "Lullaby", the band's fourth single. After meeting the producer, the band agreed to work with him on their second album. However, the collaboration was short-lived; sessions at London's Abbey Road proved difficult. Spector is said to have dismissed Ben Byrne's drumming, and proved difficult to work with. Only two tracks made the band's second album: the title track, "Silence Is Easy", and "White Dove". The band co-produced seven of the other tracks with Danton Supple and former The Stone Roses and Radiohead producer John Leckie was brought in to oversee the recording of "Shark Food". The first single was "Silence Is Easy", which made the Top Ten (#9, the band's highest placing). The album spawned just three singles; the second of which, "Born Again" had evolved from a B-side to "Poor Misguided Fool", released in early 2002. The song was re-recorded for the album, and cut down for a radio edit. "Four to the Floor", which was remixed by Thin White Duke, became a popular club hit. Walsh wanted the track to become the band's "I Am the Resurrection", something to be played in "indie discos everywhere". The album charted well, but sales were sluggish in comparison to the band's first album. The release dropped out of the Top 40 soon thereafter. A full UK Tour began in Autumn 2003 shortly after the release of the album, culminating at London's Brixton Academy. The show featured the only performance before their American tour in 2006 of "Restless Heart", the closing track on the Silence Is Easy album. Mark Collins, from The Charlatans joined Starsailor for all dates between August 2003 to December 2004, playing additional and lead guitar.

Who did they collaborate with on the album?
the band agreed to work with him on their second album.