MetroPCS Inc. (NYSE: PCS) is joining forces with Rhapsody Networks to offer its subscribers unlimited music, in a bid to get them to sign up for its most expensive unlimited wireless service plan.

The pre-paid operator is offering the unlimited music-streaming-and-download service to its subscribers with Android handsets and $60 per month unlimited talk, text and Web plans. As of the second quarter, about one-fourth of its customer base owned smartphones, and 40 percent of handsets sold in the quarter were based on Android's OS. (See MetroPCS Explores Spectrum Options.)

Why this matters
MetroPCS is taking a cue from its contract-free competitor Leap Wireless International Inc. (Nasdaq: LEAP), which recently launched its own unlimited music service, Muve Music. Leap's all-you-can-eat music, offered with a $55 subscription, has already signed up 100,000 customers in its first five months. (See Cricket's Muve Music Adds 100K Customers and Cricket Comes With Music Too.)

Metro is also hoping offering music as a value-added service will help it move more customers to smartphones and higher-end service plans, as well as provide a showcase for its new Long Term Evolution (LTE) network.

This is also an important win for Rhapsody as it faces increasing competition from Spotify , recently launched in the U.S., and other free music streaming services. (See Spotify Hits US 3G Networks.)

For more
Music is slowing becoming a bigger part of mobile, something the record industry is counting on. Here's more:

• HTC Feels the Beats for $300M
• Leap Hopes Music Will Muve It Nationwide
• Leap Muves Music to All Its Markets
• Cricket Makes Music in 13 New Markets
• Comes With Carriers?
• Top 10 Apps LTE Will Super-Charge
• App Focus: Premium Shazam Comes to Android

— Sarah Reedy, Senior Reporter, Light Reading Mobile