SanDisk and the record companies are launching a new music format today dubbed slotMusic. The company hopes music companies will publish entire albums on SanDisk flash memory cards that are smaller than a postage stamp and are expected to replace the music CD.

In an age of downloadable music, the new  slotMusic format for distributing MP3 songs is a long shot. But it has heavy-duty support. SanDisk has been trying out the idea for a number of years. The format is now being embraced by four major record companies: EMI Music, Sony BMG, Universal Music Group and Warner Music Group. Major retailers supporting it include Best Buy and Wal-Mart. While these are big players, the move seems like a stop-gap measure to push back against the $1-per-song downloading trend that has taken over the indsutry. The companies are hoping that convenience of the memory cards will shift behavior patterns.

The slotMusic cards can fit into mobile phones, but they won’t play on Apple’s iPhone or iPod products. That may be a killer problem, since more than 4 billion songs have been downloaded from Apple’s iTunes music store since 2003. The cards store 1.1 gigabytes of data and can stream music at a high-quality level of 320 kilobytes per second. Albums are expected to cost about $15 and will be stocked near the ever-vanishing CD racks in stores.