LONDON — Backstage astatine the Royal Festival Hall, 1 of London’s grandest classical euphony venues, James Buckle, the bass trombonist for the Philharmonia Orchestra, braced himself to bash thing he’d ne'er done before: play the familiar opening of Beethoven’s Fifth Symphony.

Trombone players usually walk astir of the symphony waiting successful soundlessness astatine the backmost of the orchestra, ignored by the audience, lone getting the accidental to play successful the piece’s final, euphoric movement. But acknowledgment to the fashionable caller video crippled Trombone Champ — a benignant of Guitar Hero for brass players — Buckle was having a spell astatine its exhilarating opening arsenic if helium were 1 of the archetypal violins. “I person to admit I’m a spot excited,” helium said.

Buckle, 29, who gamely agreed to trial retired Trombone Champ past weekend, gripped a mouse, which helium would determination up and down to alteration the transportation of his virtual trombone, and placed his near manus connected the laptop’s abstraction bar, which helium would deed to play notes. Then, the crippled began. As a flurry of notes moved crossed the screen, from close to left, Buckle desperately tried to support up. But things did not spell according to plan, and what came retired of the laptop’s speakers was little a Beethoven masterwork than an out-of-tune mess.

“God, it sounds similar maine warming up!” Buckle said.

As the tune ended, Buckle leaned back, grinning successful delight. “This is going to dependable truly sad,” helium said, “but it felt genuinely large getting to play that.”

Over the past week, Trombone Champ has go a astonishment improvement online, with the game’s fans going connected societal media to station clips of their fraught attempts to play “Auld Lang Syne,” “The Star-Spangled Banner” and Richard Strauss’s “Also Sprach Zarathustra.” Last week, a clip of idiosyncratic mangling Rossini’s “William Tell Overture” was retweeted implicit 40,000 times.

The crippled has attracted rave reviews. Christopher Livingston, in PC Gamer magazine, called it “a superior crippled of the twelvemonth contender” (Livingston added that helium wasn’t joking, successful lawsuit anyone wasn’t sure). A fistful of gamers person been truthful enamored by it, they person built trombone-shaped controllers truthful they tin play the crippled much similar existent musicians.

But what bash existent trombone players marque of it?

Trombone Champ does not instrumentality the trombone, oregon trombonists, precise seriously. It calls the players “tromboners,” for a start. Before each song, it displays pseudofactoids astir the trombone (“in England, trombone is spelt troumboune,” reads a emblematic one). In clips, the “tromboner” dances adjacent portion playing thing serious.

But Buckle, the nonrecreational trombonist, had lone affirmative things to accidental astir the game. “If it raises consciousness oregon means anyone wants to prime up the trombone, it’s a large thing,” helium said.

Trombone Champ is the instauration of Dan Vecchitto, a web exertion decorator astatine Penguin Random House, who — successful concern with his wife, Jackie Vecchitto — successful his spare clip makes video games successful the chamber of his Brooklyn apartment.

Vecchitto, 38, said helium came up with the thought 4 years agone portion trying to deliberation of concepts for amusive arcade games. “I conscionable got this intelligence representation of an arcade furniture with a elephantine rubber trombone attached,” helium said. After realizing that would beryllium hard to make, Vecchitto acceptable astir creating a mentation wherever players usage a rodent to emulate a trombone’s movements, which would let them to descent betwixt notes.

It was instantly wide the crippled would beryllium a comedy, Vecchitto said, and helium took each accidental to insert jokes.

Vecchitto utilized to play saxophone successful precocious schoolhouse bands, but said helium had nary acquisition of the trombone. Asked if helium consulted immoderate trombonists portion making the game, Vecchitto said, “I meant to,” past laughed. At 1 point, Vecchitto bought a integrative trombone, called a pBone, “so I had immoderate thought what this happening really feels like,” but that was arsenic adjacent arsenic helium got to in-depth research.

“I was a small acrophobic that existent trombonists mightiness instrumentality offense,” Vecchitto said, “but for the astir portion they’ve been highly supportive.”

Vecchitto said helium had received 1 antagonistic email from a jazz trombonist telling him the crippled was disrespectful to the instrument, but different a big of players, including several trombone YouTubers, has praised it.

Several trombone players said they thought the crippled was a affirmative showcase for the instrument. Xavier Woods, a prima wrestler for WWE who plays the trombone successful bouts and is besides a well-known gamer under the sanction Austin Creed, said that helium had not expected the crippled to clasp his attention, but that helium had ended up playing it for hours.

The trombone’s joyousness is its versatility, Creed said: “You tin marque unthinkable jazz connected it, you tin play astatine Carnegie Hall and the astir beauteous sounds volition travel retired of this horn, and past you tin play astatine a kid’s clown day and conscionable marque everyone giggle.”

Alex Paxton, a British composer, said successful his London flat that clips of Trombone Champ were truthful filled with out-of-tune notes and microtones that they “had each the hallmarks of large experimental music.” Paxton past sat down to effort the crippled for himself. After a fewer tries, helium appeared to turn weary of pursuing its rules, and conscionable started waggling the rodent up and down rapidly to make a barrage of noise. As helium did, the surface started glowing a scope of psychedelic colors. Then, Paxton went and got 1 of his ain trombones and tried to play a duet with the game.

Trombone Champ was not overmuch similar playing a existent instrument, Paxton said afterward. In existent life, helium said, notes usually spell awry for beginners erstwhile a player’s lips are successful the incorrect position, thing the crippled does not approximate. Even so, the crippled “shows however the trombone tin beryllium a licence to beryllium weird, to beryllium yourself,” Paxton said.

Whether the crippled volition promote immoderate online “tromboners” to instrumentality up the existent instrumentality remains to beryllium seen. At the Royal Festival Hall, Buckle, of the Philharmonia, invited a colleague, Joseph Fisher, who plays the viola successful the orchestra, to springiness it a try. After struggling with immoderate trombone Tchaikovsky connected the laptop — and giggling erstwhile helium fluffed a enactment and the connection “Meh” appeared onscreen successful large letters — helium was asked if helium mightiness power instruments.

“Not to the trombone,” Fisher said, “but I’m decidedly going to get the game.”