microSD
Secure Digital, officially abbreviated as SD, is a proprietary non-volatile flash memory card format developed by the SD Association (SDA) for use in portable devices.
The standard was introduced in August 1999 by joint efforts between SanDis ...
memory card
A memory card is an electronic data storage device used for storing digital information, typically using flash memory. These are commonly used in digital portable electronic devices. They allow adding memory to such devices using a card in a so ...
developed by
SanDisk
SanDisk is a brand for flash memory products, including memory cards and readers, USB flash drives, solid-state drives, and digital audio players, manufactured and marketed by Western Digital. The original company, SanDisk Corporation was acquire ...
preloaded with music in
MP3
MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in the United States and elsewhere. Origin ...
format. They were first available at
Wal-Mart
Walmart Inc. (; formerly Wal-Mart Stores, Inc.) is an American multinational retail corporation that operates a chain of hypermarkets (also called supercenters), discount department stores, and grocery stores from the United States, headquarter ...
and
Best Buy
Best Buy Co. Inc. is an American multinational consumer electronics retailer headquartered in Richfield, Minnesota. Originally founded by Richard M. Schulze and James Wheeler in 1966 as an audio specialty store called Sound of Music, it was rebra ...
stores in October 2008. The current selection of songs comes from
Universal Music Group
Universal Music Group N.V. (often abbreviated as UMG and referred to as just Universal Music) is a Dutch– American multinational music corporation under Dutch law. UMG's corporate headquarters are located in Hilversum, Netherlands and its ...
,
Sony BMG
Sony BMG Music Entertainment was an American record company owned as a 50–50 joint venture between Sony Corporation of America and Bertelsmann. The venture's successor, the revived Sony Music, is wholly owned by Sony, following their buyout o ...
,
Warner Music Group
Warner Music Group Corp. ( d.b.a. Warner Music Group, commonly abbreviated as WMG) is an American multinational entertainment and record label conglomerate headquartered in New York City. It is one of the " big three" recording companies and t ...
and
EMI Music
EMI Group Limited (originally an initialism for Electric and Musical Industries, also referred to as EMI Records Ltd. or simply EMI) was a British transnational conglomerate founded in March 1931 in London. At the time of its break-up in 201 ...
. As of mid-2011, SanDisk's website lists a total of 14 albums available in the SlotMusic format.
The audio files contain no
digital rights management
Digital rights management (DRM) is the management of legal access to digital content. Various tools or technological protection measures (TPM) such as access control technologies can restrict the use of proprietary hardware and copyrighted works. ...
, and are encoded at minimum
bitrate
In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time.
The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...
s of 256 to 320 kbit/s.
A slotMusic albums may also include high-quality images and videos in multiple formats. The contents of each microSD card may be altered by the user, enabling them to add or remove files from the slotMusic card as desired. Another type of card,
slotRadio
slotRadio was a proprietary format developed by SanDisk that delivered music on a microSD memory card. Up to 1,000 songs were preloaded on microSD cards which were DRM protected. Users had no direct access to the music to copy songs, organize ...
, was developed in 2009 which had radio-like controls. A slotRadio card had more restrictions on how it worked, such as not being able to backtrack to a previous song.