People: Britney Performing At House of Blues Tonight

Britney Spears is scheduled to hit the stage for a brief performance at the House of Blues in San Diego on Tuesday night, sources close to the singer tell PEOPLE.

"The set is only going to be about 10 minutes long," says the Spears source. "It's only a few songs and she won't showcase new material."

Rumors that Spears has been planning a comeback performance have been swirling for days. Last week, she was reportedly scheduled to perform three songs at Hollywood club Ivan Kane's Forty Deuce, but plans fell through at the last minute,

The owner of the Millennium Dance Complex, where Spears has been training regularly for the last few weeks, says the singer has been working on material which resembles her earlier hits.

"They'll be in the style we are all used to, the pop thing," says Robert Baker. "But she's got bigger plans brewing, with music and dancing that's a break from her old stuff. She's really excited about that."

As for Tuesday's show, the source says it's just the beginning. "It's kind of warming up. That's probably the best way to describe it." That is, if the show goes on.

Spears's last major performance was in June, 2004 during her Onyx Hotel Tour in Dublin, Ireland.

Spears is also planning several shows this week including ones at the House of Blues in Anaheim, Calif. on Wednesday, the Los Angeles House of Blues on Thursday, and the House of Blues Las Vegas inside Mandalay Bay on Sunday.
Source: People

When I found out a few days ago she was only doing old material, I was kind of bummed, not gonna lie. Wanted to keep it on the DL tho...