Apple spokesman Steve Dowling confirmed the purchase Sunday, but would not provide any further information, including how much the deal was worth.
"Apple buys smaller technology companies from time to time and we generally do not comment on our purchase or plans," he said.
Lala has developed an application - not yet available to the public - that allows users to buy the right to stream songs from a digital locker for an unlimited time on their iPhones for 10 cents each.
The song quality is lower than what Apple's iTunes songs offer, but tracks can played in seconds, and cost much less than the songs on iTunes, which generally are priced at 69 cents to $1.29 each.
Lala, a private company based in Palo Alto, Calif., was launched in 2006 with $35 million in venture capital from Bain Capital LLC, Ignition Partners and Warner Music Group Corp. Lala began as an online CD-trading site but relaunched in October 2008 as a music retailer.