Phil Spector - Love Stunned By Phil Spector's Surprise Vocal

The album - A Christmas Gift for You - is packed with classic festive songs and has become a staple soundtrack to the holiday season.

Love provides lead vocals for four tracks on the record, including White Christmas and Christmas (Baby Please Come Home), and was excited to hear the finished product - but she was left speechless by the closing song Silent Night, which features an eerie vocal segment by the famed producer.

And Love is adamant Spector included the track on the album to remind all his artists he was "the boss".

She says, "At first, he tells me we'll all sing Silent Night. And we went in there, recorded, 'Si-i-lent night,' really cute. Then when the record came out, he was on it. We was like, 'What the...?'

"He's that type of person that - even though he's not on any of the sessions except as the producer - he wanted people to know he is the boss."