"You're asking the wrong person," Mel B, 43, told Entertainment Tonight when asked about the potential celebrities joining them onstage. "I'm just gonna say yes, of course it can happen. I'd have to check in with the other girls first."
"I'm the one [who's] always thinking about stuff like that, always," she said. "And I'm the first one to say, 'Let's do this and we'll introduce Taylor Swift on one song or Adele or Katy Perry.' I think that's a great idea 'cause at the end of the day, it has to be a celebration."
The girl group wants the six-date reunion tour, dubbed The Spice Up Your Life tour, to feel like an enormous party to those in the audience.
"We want our fans to know that this is going to be a celebration and we're going to go back in time," Mel B said. "You know, it's going to be like when you first heard that song."
Although Scary Spice (Mel B), Sporty Spice (Mel C), Baby Spice (Emma Bunton) and Ginger Spice (Geri Halliwell) won't be joined by Posh Spice (Beckham), Mel B said they're not holding any grudges.
"Yeah it's disappointing, but it's not in some ways, because you have to be respectful of what she wants to do and you can't force anybody to do anything," the America's Got Talent judge said. "But I still live in hope that she is going to join us, and she is a part of our band."
Despite Beckham's exclusion from the tour, each member is set to make a hefty amount for the six dates: $3 million each, to be exact. TMZ reports that the women will rake in nearly $550,000 each per show, totaling $3.2 million total. Should tickets sell out and a second leg be announced, that sum could rise to $6.5 million.
Had Beckham joined in on the fun, each woman reportedly potentially could have taken home as much as $13 million. But the 44-year-old fashion designer announced earlier this month that she'd be sitting this one out.
"Today marks a special day for the girls as they announce the first tour dates since we performed together in 2012!" she explained on Instagram. "I won't be joining my girls on stage again but being in the Spice Girls was a hugely important part of my life and I wish them so much love and fun as they go back on tour next year. know they will put on an amazing show and the fantastic fans past and present are going to have a wonderful time!"
The tour will kick off at Manchester's Etihad Stadium on June 1 before traveling to Coventry's Ricoh Arena on June 3, Sunderland's Stadium of Light on June 6, Edinburgh's BT Murrayfield Stadium on June 8, Bristol's Ashton Gate Stadium on June 10 and London's Wembley Stadium on June 15.
Tickets are currently on sale.