In a week that will see heavy coverage of MySpace Music when it launches, SanDisk (NSDQ: SNDK) has announced an ambitious venture to sell its microSD memory cards pre-loaded with DRM-free MP3 music from all the four majors EMI Music, Sony BMG, Universal Music Group, and Warner Music Group. The service, dubbed “slotMusic”, will launch this coming holiday season in U.S., at Best Buy and Wal-Mart (NYSE: WMT), among others, and then will be launched in Europe, though no specific timeline was given.

The MicroSD format, a SanDisk invention, is used mainly in mobile phones, and also in some MP3 players. When slotMusic goes on dale, these cards will be packaged with a tiny USB sleeve so that they can be compatible with various PCs and laptops, and any other device with a USB connector, including say an in-car sound system. The MP3-based music tracks will be played back at up to 320 kbps, the company said. With 1GB of capacity, slotMusic cards can hold songs, as well as liner notes, album art, videos, and other content that an artist/labels may choose.

More after the jump...

On pricing, the company hasn’t release details, but NYT has some numbers from sources: It will sell for $7 to $10, sources tell NYT. A 1 GB MicroSD card is around $10-15 these days, so it seems like value for money, even if users end up erasing the songs and use it for something else (That leads to the obvious pun of “Comes With Memory Card,” given Nokia’s (NYSE: NOK) Comes With Music service, which offers free unlimited music downloads with some phones.)

There have been previous attempts by SanDisk and others to sell music and content cards through retails, though with limited success. Also, in the age when CDs are being replaced, any other physical alternative seems a bit counterintutive. At best, this is a bid for the ono-iPod crowd. Any chances at success also depends on the depth of catalog, but it seems that at least UMG won’t have lots to begin with. AP: Rio Caraeff, EVP of Universal Music Group’s eLabs digital music unit, said the label will initially release about 30 titles in the slotMusic format. The titles will include old and new albums, such as one by singer Akon. Asked whether he sees the format taking the place of the CD, Caraeff said, “I think we would certainly hope that would be the case, but I don’t think we are so tied to that.”

SanDisk is also in the midst of a takeover attempt by Samsung, which made its $5.85 billion public bid for the company last week, but the company rejected it as too low.