Rolling Stones Tour 2013 UPDATE: Gary Clark Jr. to Join Stones for Boston Show

The Rolling Stones are still adding to the celebrity guest list as the group continues on its 50 & Counting Tour, celebrating its fiftieth anniversary. The band announced Tuesday that blues rocker Gary Clark Jr. will join the Stones at its Wednesday night show at Boston's TD Bank Garden.

Popular musical guests from all genres have been a common theme throughout "50 & Counting." Win Butler of The Arcade Fire joined the group in Montreal last weekend, and Taylor Swift performed with the band in Chicago last week. Othere guests have included Katy Perry, Dave Grohl, Tom Waits and Sheryl Crow. The trend continues from the few shows the Stones played in 2012, which featured guest spots from Eric Clapton, Bruce Springsteen and Lady Gaga.

The band hasn't announced what song Clark will join them for, but fans can expect that the guitarist will be singing and playing with the band (Butler stuck to vocals on Sunday's rendition of "The Last Time").

Wednesday's show will be the third time Clark has appeared with the Stones during his career. He played "Going Down," a Freddie King blues classic, along with the group during a New York City show last year and joined John Mayer and the band for the same song in Newark, NJ. Never assume, but there's a good chance that "Going Down" will be the song of choice in Boston as well. Clark backed vocalist Mick Jagger (along with an all-star guitar cast of B.B. King, Buddy Guy and Jeff Beck) at the Red, White and Blues concert at The White House last year.

There is no official schedule of who will join the band where. The last few stars, including Butler and Swift, have been announced a few days prior to the show. Others, like Grohl, have seemingly just shown up.