Singer/songwriter Elvis Costello is slated to begin selling some of his best-known albums in downloadable MP3 format through EMusic.com on Monday (Feb. 28), EMusic said. The 12 albums to be offered span his 1977 classic debut, My Aim Is True, through 1986's Blood & Chocolate and include such hits as "Alison," "Pump It Up," "Radio Radio" and "Everyday I Write the Book." In the past year, EMusic has become one of the Internet's leading sellers of downloadable tracks, offering work by Phish, Bush, They Might Be Giants and Tom Waits. Costello's most recent album was the 1998 collaboration with songwriter Burt Bacharach, Painted From Memory.