According to Billboard chart statistics, Chicago is second only to the Beach Boys as the most successful American rock band of all time, in terms of both albums and singles. Judged by album sales, as certified by the R.I.A.A., the band does not rank quite so high, but it is still among the Top Ten best-selling U.S. groups ever. If such statements of fact surprise, that's because Chicago has been singularly underrated since the beginning of its long career, both because of its musical ambitions (to the musicians, rock is only one of several styles of music to be used and blended, along with classical, jazz, R&B, and pop) and because of its refusal to emphasize celebrity over the music. The result has been that fundamentalist rock critics have consistently failed to appreciate its music and that its media profile has always been low. At the same time, however, Chicago has succeeded in the ways it intended to. From the beginning of its emergence as a national act, it has been able to fill arenas with satisfied fans. And beyond the impressive sales and chart statistics, its music has endured, played constantly on the radio and instantly familiar to tens of millions. When, in 2002, Chicago's biggest hits were assembled together on the two-disc set The Very Best of Chicago: Only the Beginning and the album debuted in the Top 50, giving the band the distinction of having had chart albums in five consecutive decades, the music industry and some music journalists may have been startled. But the fans who had been supporting Chicago for over 30 years were not.
Despite the personnel changes over the years, the group is still active four decades after its founding. They are one of the few major rock groups that have never broken up or even taken an extended hiatus. Four of the six surviving founding members (major songwriters Lamm and Pankow, plus Loughnane and Parazaider) remain to this day providing continuity, while Jason Scheff has over 23 years with the band, Tris Imboden over 18, and Keith Howland over 13.
As a new century turned, the band licensed their entire recorded output to Rhino Records (after years with Columbia Records and Warner Brothers as well as their own short-lived label). In 2002, Rhino released a two-disc compilation, The Very Best of Chicago: Only The Beginning, which spans the band's entire career. The compilation made the Top 40 and sold over 2 million copies in the US. Rhino has also begun releasing remastered versions of all of the band's Columbia albums, each including several bonus tracks; and in 2005 they released a compilation entitled Love Songs.