A new physical music format has been launched by SanDisk and the big four record labels, EMI Music, Sony BMG, Universal Music Group, and Warner Music Group.

Dubbed "slotMusic" the format is based on the microSD cards that are due to launch soon available with pre-loaded, high quality, DRM-free MP3 music.

slotMusic cards work with any microSD-enabled mobile phones, car stereos or MP3 player as well as Mac, Linux and Windows computers with the bundled USB sleeve.

The MP3-based music tracks will be played back at up to 320kbps, and cards will also hold liner notes, album art, videos, and other creative content that an artist may choose.

A selection of slotMusic cards will be available soon at stores throughout the US, including Best Buy and Wal-Mart, with Europe to follow.

A complete list of slotMusic albums, availability and pricing will be announced in time for Christmas.