Universal Music Group has become the latest label to release albums as part of Apple’s Mastered for iTunes initiative, including music from artists like Madonna, Paul McCartney, Kaori Muraji, U2, John Coltrane and Bon Jovi.

As the name indicates, tracks in the Mastered for iTunes collection have been encoded specifically for distribution via the iTunes Store, with the goal of delivering high quality audio. It reflects the digital audio technology advances that have been made during the past decade.

When the first iTunes store went live in April 2003, it had a catalog of only about 200,000 songs. Most of the sold downloads were 128 kbps AAC files encoded from the original CD masters. Apple now offers what it calls iTunes Plus: music sourced from high-resolution audio and encoded as a variable bit rate (VBR) 256 kbps AAC file, resulting in higher fidelity and a greater dynamic range.

Among the new albums included in Universal’s Mastered for iTunes release slate are Madonna’s MDNA, Paul McCartney’s Kisses On The Bottom and classical guitarist Kaori Muraji’s Soleil – Portraits 2. Also in the project are back catalog albums like U2’s Achtung Baby, John Coltrane’s A Love Supreme, and Bon Jovi’s Slippery When Wet and Have a Nice Day.

Related links:

Mastered for iTunes section of the iTunes Store –

Further information on Mastered for iTunes –

Photo of Paul McCartney courtesy of JBL, the sound equipment company for whom he serves as a brand ambassador.