Janet Jackson is cleaning out her closet, putting her wedding dress and dozens of her stage costumes up for auction in May for the first time.

Julien’s Auctions said on Thursday that the five-time Grammy winner is selling more than 1,000 of the costumes she wore on stage, on tour, on red carpets and in music videos over the past four decades.

Jackson has kept the costumes in storage for years.

“Janet has never done an auction before. In fact, we find it very hard to find items at auction, any auction, from Janet Jackson because she’s kept everything,” Martin Nolan, executive director of Julien’s Auctions, told Reuters.

“It’s cathartic for her... she’s happy to let them go and to raise money for a charity that’s really important to her,” Nolan said.

Some of the top items in the May 14-16 sale in Beverly Hills include the wedding outfit from Jackson’s second, secret marriage, to dancer Rene Elizondo Jr in 1991. The marriage was not publicly known until the couple split eight years later. The ivory bodysuit with a tiered ruffle skirt dress carries a pre-sale estimate of $2,000 - $3,000.

The singer, 54, is also parting with the original Rhythm Nation Jacket from her eponymous 1990 world tour. It carries a pre-sale estimate of $6,000 - $8,000.

The floor-length metallic silver coat that Jackson wore in her 1995 music video for “Scream” with her brother Michael Jackson is expected to sell for up to $8,000. A 17th century-inspired ensemble of cropped riding jacket and thigh high boots she donned during her 1993-95 world tour has an estimate of $4,000 - $6,000.

The singer’s most famous outfit - the black leather bustier that was ripped, briefly exposing her breast at the 2004 Super Bowl halftime show - is not included in the auction.

Jackson is also selling her 1956 Chevrolet Cameo Pickup truck, which has been restored to its original condition. It is expected to fetch between $50,000 - $70,000.

A portion of the auction proceeds will go to the Christian child sponsorship group Compassion International. Jackson will also give 100% of sales of a limited edition three volume set of auction catalogs, offered at $800, to the nonprofit.