LOS ANGELES — Multiple movie studios passed on the opportunity to make “Rocketman,” an R-rated musical fantasia about Elton John’s hedonistic breakthrough years. Too gay. Too expensive. Too reliant on an unproven star.

But one film company, the down-on-its-luck Paramount Pictures, saw the audacious project as a chance to prove something to both Hollywood and Wall Street — namely that, to borrow a reference from Sir Elton, it’s still standing.

Now comes the moment of truth.

“Rocketman” will arrive in theaters on May 31 as perhaps the most ambitious movie of Hollywood’s summer season, a four-month period that typically accounts for 40 percent of annual ticket sales and relies overwhelmingly on franchises. Starring Taron Egerton and costing an estimated $120 million to make and market worldwide, “Rocketman” trails glitter — a million Swarovski crystals adorn the costumes and eyewear — and depicts gay sex, a first for a major studio. Mr. Egerton, 29, known for the “Kingsman” action comedies, did all of his own singing, reinterpreting classics like “The Bitch Is Back.” There is intricate choreography (one stylized scene finds an entire London neighborhood dancing in formation) and an orgy musical number set to “Bennie and the Jets.”

Depending on its box office performance, “Rocketman” could have wide ripple effects. Paramount has delivered nine consecutive quarters of improved financial results for Viacom, its corporate owner, but a turnaround is still tenuous. A big hit — and one that’s not a sequel, spinoff or reboot, at that — would provide a morale boost and send an important message to Hollywood’s creative community and Viacom investors: that even in the age of Netflix and Marvel, Paramount can deliver.