On Tuesday, a group of Seattle-based musicians including Macklemore, Sir-Mix-A-Lot, and former GNR bassist Duff McKagan signed a letter urging Mayor Tim Burgess and city council to consider local entrepreneur Chris Hansen’s proposal to remodel the aging KeyArena into a music and arts space using private funding.

However, it may be too late—as it appears the city is moving forward with a proposal from another group to redevelop KeyArena into a large-scale music and sports stadium.

The Hansen proposal for KeyArena includes a 6,200-seat indoor concert space, a 3,000-seat covered amphitheater, and a 500-seat theater, which, as a mid-size venue, the letter states, would “fill a crucial gap for the local music community and touring artists, while creating a world-class outdoor viewing experience that is currently missing in Seattle.”

The facilities, the letter continued, would serve as a ‘civic space’ that would benefit other Seattle Center arts organizations like SIFF, The Vera Project, KEXP, MoPOP, Seattle Opera, and Pacific Northwest Ballet, as well as be a fully-functioning venue for festivals like Northwest Folklife Festival and Bumbershoot. Large scale concerts and sports events, the group says, could be held downtown at Hansen’s proposed 16,000-21,000-seat SODO Arena. More about their proposal for KeyArena can be found here.

But it looks like the city has decided to go with another option already: “The City of Seattle is currently reviewing one proposal for the redevelopment of KeyArena,” said the Director of Communications for the Seattle Office of Economic Development and Office of Film + Music, Joe Mirabella. And that proposal is from LA-based investment firm Oak View Group.

The Oak View Group’s proposal for the former Sonics home, which would also be privately financed, is quite different than Hansen’s: $600 million for a large-scale 19,000 seat venue “ready for professional hockey, basketball, and music” and designed to attract an NBA or NHL team.

They’ll also partner with ticketing company LiveNation, which will help them attract “top-level concert,” according to the Oak View Group. Mirabella says all of these factors and several more made the Oak View Group’s proposal an attractive one:

OVG also has very close relationships with the NHL and NBA. Live Nation has been a promoter in this region for decades. They are an equity partner, so music will be central to the long-term success of the project. OVG also announced Pearl Jam as a resident artist who will have regular performances at the venue.

The Oak View Group’s full proposal can be found here.

In an editorial for the Stranger, Seattle musician Ben London says that Oak View’s partnership with ticketing giant LiveNation is problematic and that the Hansen project would remain “promoter neutral.” Additionally, London says the city is not acting in good faith on an agreement they had made with the Hansen group six years ago, which he says was overlooked because the Murray administration had their eye on OVG’s proposal from the beginning:

The initial Hansen proposal started during the McGinn administration and was tainted in Murray’s eyes the minute he came into office. Murray and his administration created a process that blocked open discussion of the Hansen group’s proposals while creating a request for proposal process for KeyArena that was so narrow in scope, it precluded any larger creative ideas. His administration then heavily favored one of the proposers, LA-based Oak View Group, from Day One. It’s one of the reasons AEG, the only other bidder, withdrew its proposal out of protest.

But the Office of Economic Development says that the Hansen/SODO Arena group missed the deadline to submit their RFP months ago. On September 17, the office issued a statement that read: “If the SODO Arena Group was interested in redeveloping KeyArena, they should have submitted their proposal during the RFP process, which would have shown a willingness to work with the City on this project. They did not submit a proposal and continue to show no interest in working in partnership with the City.”

The MOU (Memorandum of Understanding) that the city negotiated with the Oak View Group includes the option to renew a 39-year lease, and outlines the company’s responsibilities for traffic mitigation, environmental reviews, and moving local businesses that will be impacted by KeyArena construction.

If the MOU is approved by December 4, the arena will be scheduled to open October 2020.

However, there still may be a chance for Hansen’s group to get in the mix, Mirabella says—if they can find an NBA team, and quick: “The City continues to honor the MOU with the SODO Arena group that was signed more than five years ago. Under the MOU they have until December 3, 2017 to secure an NBA team before moving forward.”