Consistently one of the hottest concert tickets each summer in the Twin Cities, Rock the Garden could be two of the hottest tickets next year.

The annual rock 'n' roll bash outside Walker Art Center will expand from a one-day affair to a two-day party in 2014, scheduled June 21-22 (a Saturday and Sunday). That could mean twice as many bands, and more profits for the nonprofit organizations that put it together.

Staged near the Minneapolis Sculpture Garden on a hillside overlooking the downtown skyline, Rock the Garden was devised in 1998 as a way to drive up membership and raise funds and awareness for the Walker.

Minnesota Public Radio's hip music-head station 89.3 the Current signed on as a partner in 2008 with the same goals. The event has grown in size and popularity since then with headlining bands pulled straight off the Current's playlist, such as Metric, the Hold Steady, My Morning Jacket and MGMT.

In recent years, nearly all of the 10,000 tickets have sold out exclusively to Walker and MPR members, who get first access. The two-day Basilica Block Party, by comparison, offers room for about 16,000 fans per day but rarely sells out before show time.

Rock the Garden netted the Walker about $186,000 in 2012, according to a museum spokesperson. The event should clear much more with a second day of ticket and concession revenue, since a considerable portion of its costs is in setting up the stage and prepping the Walker grounds — expenses that are the same whether it's a one- or two-day concert.

"The key word here is still 'benefit,' " said Doug Benidt, the Walker's assistant curator of performing arts. "Doing it this way is for the greater benefit of both organizations."

Noting the extra hours Walker and Current staff will have to work on the concert, Benidt joked, "I think we might need to find a coffee sponsor this year."

The extra day has gotten approval from city officials as well as the Lowry Hill and Kenwood-Isles neighborhood associations. "We're supportive of the Walker's efforts and appreciate its involvement in the neighborhood," said Lowry Hill association president Maureen Sheehan, adding that she hopes "the lines of communication are kept open" as the event nears.

Much planning remains, particularly on the music lineup. One band might perform both days. It might be all different bands each day. One day might be reserved for local bands, who "will definitely play a bigger role," Benidt said.

Once performers are in place, that will dictate the price and breakdown of tickets, with two-day passes likely to be offered alongside single-day. Look for the full lineup and ticket announcement in mid-April.

Chris Riemenschneider • 612-673-4658