Song written by Ricky Wilde, Scarlett Wilde and Shane Lee.
Originally recorded as a demo called 'It's Your Birthday' by Scarlett in 2012, it was eventually recorded by Kim.
Eighth track on the album Here Come the Aliens. Released as the third single from the album.
There are three versions of 'Birthday': the album version, a radio edit and a live version recorded in Munich, released on the album Aliens Live.
Kim about 'Birthday'
'Birthday was inspired by, amongst others, a band called the Sounds and of course a bit of Blondie, and 'Birthday' really talks about partying like it's your birthday every day of your life. 'cos, you never know when you're not gonna be here so you may as well make today great. (Track by track video, YouTube, March 12, 2018)
Drums: Jonathan Atkinson
Bass: Paul Cooper
Guitar: Neil Jones
Keyboards, guitar: Ricky Wilde
Backing vocals: Kim Wilde, Ricky Wilde, Scarlett Wilde