NEW YORK (OSV News) – Arthur Fleck may be imprisoned and on trial for five counts of murder in the sequel "Joker: Folie a Deux" (Warner Bros.). But, on the upside, this follow-up to 2019's "Joker" does give Joaquin Phoenix's emotionally tortured, homicidal villain a chance to demonstrate his mastery of the great American songbook.

Such is the unstable chemistry of director and co-writer Todd Phillips' misguided attempt to feature the DC Comics-based baddie -- traditionally one of Batman's would-be nemeses -- in a musical romance as Lady Gaga's Lee Quinzel wins his heart. With her at his side, so we're informed, he's got the world on a string.

Cue a series of set pieces meant to evoke both the Golden Age of Hollywood and the television variety shows of the 1970s, Sonny and Cher's in particular. In between, scenes of the legal proceedings against the Joker explore the degree to which his alter ego is or is not schizophrenic and therefore not legally responsible for his actions.

That's the line of reasoning championed by Fleck's lawyer, Maryanne Stewart (Catherine Keener). But his newfound lover decries it, believing Fleck and his clown-painted persona to be one.

The screenplay, on which returning helmer Phillips collaborated with Scott Silver, throws in some implicit social commentary about the resemblance between high-profile court cases and mass entertainment. But the upshot is a long, grim, ultimately unrewarding slog made suitable for few -- more by its gritty atmosphere than by an accumulation of objectionable ingredients.

The film contains much harsh but mostly stylized violence, a semi-graphic nonmarital encounter, full and rear male nudity in a nonsexual context, mature themes, including child physical and sexual abuse and an out-of-wedlock pregnancy, a couple of profanities, at least one milder oath, pervasive rough language, several crude terms and obscene gestures.The OSV News classification is L -- limited adult audience, films whose problematic content many adults would find troubling. The Motion Picture Association rating is R -- restricted. Under 17 requires accompanying parent or adult guardian.- - -CAPSULE REVIEW"Joker: Folie a Deux" (Warner Bros.)Misguided attempt to feature Joaquin Phoenix's emotionally tortured, homicidal villain in a musical romance as Lady Gaga's Lee Quinzel wins his heart. In between set pieces meant to evoke both the Golden Age of Hollywood and the television variety shows of the 1970s, scenes of the Joker's trial on five counts of murder explore the degree to which his alter ego, Arthur Fleck, is or is not schizophrenic and therefore not legally responsible for his actions, a line of reasoning championed by his lawyer (Catherine Keener) but decried by his newfound lover. Director and co-writer Todd Phillips' second riff on the DC Comics-based baddie throws in some implicit social commentary about the resemblance between high-profile legal proceedings and mass entertainment. But the upshot is a long, grim, ultimately unrewarding slog made suitable for few -- more by its gritty atmosphere than by an accumulation of objectionable ingredients. Much harsh but mostly stylized violence, a semi-graphic nonmarital encounter, full and rear male nudity in a nonsexual context, mature themes, including child physical and sexual abuse and an out-of-wedlock pregnancy, a couple of profanities, at least one milder oath, pervasive rough language, several crude terms, obscene gestures.The OSV News classification is L -- limited adult audience, films whose problematic content many adults would find troubling. The Motion Picture Association rating is R -- restricted. Under 17 requires accompanying parent or adult guardian.- - -CLASSIFICATION"Joker: Folie a Deux" (Warner Bros.) -- OSV News classification, L -- limited adult audience, films whose problematic content many adults would find troubling. Motion Picture Association rating, R -- restricted. Under 17 requires accompanying parent or adult guardian.- - - John Mulderig is media reviewer for OSV News. Follow him on X (formerly Twitter) @JohnMulderig1.