Exactly a year after it debuted on the chart, Train's "Hey, Soul Sister" returns to the Adult Contemporary summit, logging its 20th week at No. 1.

All charts will be refreshed on Billboard.com tomorrow (Jan. 6).

Since the Adult Contemporary survey launched 50 years ago this July, only four songs have spent at least 20 weeks in the top spot:

Weeks at No. 1, Title, Artist, Peak Year
28, "Drift Away," Uncle Kracker featuring Dobie Gray, 2003
21, "Breakaway," Kelly Clarkson
21, "A New Day Has Come," Celine Dion, 2002
20, "Hey, Soul Sister," Train, 2010

Train's latest chart achievement follows the group's coronation as Billboard's top Adult Pop Songs artist of 2010. "Hey, Soul Sister" finished the past year as the No. 1 Adult Pop Songs title.

The song also placed in the upper ranks of the 2010 year-end Adult Contemporary (No. 2), Digital Songs (No. 2) and Billboard Hot 100 (No. 3) tallies.

With sales of 5 million, according to Nielsen SoundScan, "Hey, Soul Sister" stands as the eighth-most downloaded title in the digital era.

One honor eluding Train will be a victory in a major category at the 53rd Annual Grammy Awards Feb. 13. "Hey, Soul Sister" is disqualified for such fields as Record and Song of the Year since it was released digitally prior to this year's Grammy Awards eligibility period.

The song received one nomination, for a live version, for Best Pop Performance by a Duo or Group With Vocals.

"My feelings were hurt," Train lead singer Pat Monahan admits. "But, it's cool to be nominated at the same time so I'm pretty appreciative.

"It's a great reminder that that's not what we're here for. We're here because there (are) some Train fans out there and somehow they keep growing instead of shrinking.

"And, there's some music that we're supposed to provide people to maybe make their lives a little bit better. That's really why we're here."