Most likely not.
He was somewhat like this, only significantly toned down overall (except his genius, he really was unique).
But since the movie is told from Salieri's POV, clearly we're seeing Mozart through Salieri's eyes, hence his faults/traits/whatever are magnified and twisted to make us share Salieri's state of mind.
Although there is no way of knowing for sure, many experts have speculated that it is likely Mozart may have been an autistic savant, with his savant genius of course being his music. His mannerisms and rather playful personality reflect that of someone who may have been on the autism continuum. Also worth noting that his general lack of concern regarding everyday needs (paying bills/money etc) would make some sense as well. That being said, there's no way of knowing for sure.
shareThe potty-mouth stuff is based on a series of scatological letters he wrote to his cousin Maria Anna Thekla Mozart and other family members, including both his parents.
shareBased on the Bio and Classical history research I'd conducted for a music composer essay, Mozart was a unique, "unorthodox, colorful, playful, different" type of composer for his time. Half in part due the 'mistreatment' he underwent during his employment with the archbishop; who'd referred to the musical genius as a mere servant and limited Mozart's talent to studio requiems, concertos, etc. When Mozart desperately wanted to write and conduct full operas and concertos.
The other half in getting out from under the clutches of his father Leopold, who never support his son's 'unorthodox, colorful' ways, but wanted him to remain in Saltsburg as a 'good little boy' for the rest of his days.
Peanutlee33
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Allegedly, Mozart liked to tell dirty jokes, but other than that I doubt that his personality had much in common with Hulce's depiction.
shareMozart was an oddball; he was colorful and he liked dirty "bathroom" jokes. He even wrote scatological music! Perhaps the movie's depiction of him isn't so far off.
However, in the play and movie Mozart's childish personality is the exact opposite of Salieri's more serious, "regal" personality. It was meant to highlight that genius "didn't stand out" as Salieri mentioned in the salon scene: "is genius like that written on the face". In Mozart's case, the answer was obviously "no".