The Tangled Web

The Web's Most Intriguing Music-Related Issues & Destinations. This Week: iTunes, and Underworld.

MILESTONES, MORE 'TEARS': Apple's iTunes Music Store, in its eighth month of operation, has sold more than 25 million song downloads, according to the company. Apple says its songs are selling at the rate of about 1.5 million per week, a figure that increased significantly since its rollout to Windows-supporting PC systems in October.

The store's song catalog now numbers more than 400,000, with content from all five major labels and nearly 200 independents.

Among iTunes' current exclusive offers is a new EP from former Pixies frontman Frank Black. Four previously unreleased tracks -- "Don't Clip Your Wings," "A Dab'll Do Ya," "Preacher's Daughter" and "Show Me Your Tears" -- can be purchased for 99 cents each. The cuts are outtakes from Black's latest spinART album, "Show Me Your Tears."

TUNE TEACHING: Sheet-music download site has introduced a new self-teaching tool for budding guitar players. The site combines downloadable software dubbed Guitar Guru with downloadable sheet music and licensed songs. Users can practice playing from the available sheet music and guitar tablature as they listen to a song and see video of the proper left- and right-hand movements across the guitar using the software.

Guitar Guru shows examples of how to create each guitar sound within a given song, from vibratos and sustained notes to bends. Multiple guitar parts are shown for each song.

MusicNotes is launching the software with a stable of well-known classic guitar songs, including Led Zeppelin's "Stairway to Heaven," Van Halen's "Eruption," B.B. King's "The Thrill Is Gone," Lynyrd Skynyrd's "Sweet Home Alabama" and Van Morrison's "Brown Eyed Girl."

UNDERWORLD B. FREE: An hour-long concert by electronica faves Underworld is available for free RealAudio streaming at BBC's Radio 1 Web site. The show, recorded at London's Maida Vale studios, was originally broadcast on John Peel's BBC1 show, and is accompanied on the site by photos and reviews of the performance.