The little secret behind Sufjan Steven''s acclaimed Illinois is that it was originally conceived as a double album, culminating in a musical collage of nearly 50 songs. But as the project began to develop into an unwieldy epic, common sense weighed in-as did the opinions of others-and the project was cut in half. But as 2005 came to a close, Sufjan returned to the remaining songs on his 8-track. What he uncovered went beyond the merits of nostalgia. Sufjan gleaned 21 tracks from remaining material; some songs were in finished form, while others were merely outlines. Most of the material required substantial editing, new arrangements or vocals, and much of the work was done at the end of 2005 or in January the following year. As the title song ''The Avalanche'' bemuses, ''I call you once my friends,'' Sufjan took in the odd musical misfits and gathered them together like a party of good friends.