“The Life and Trials of Aimee Semple McPherson,” as the show is subtitled, are actually much more fascinating than you would gather from this formulaic Broadway musical...“Scandalous'...condenses and rearranges McPherson’s story to fit smoothly into the familiar grooves of celebrity biography. In the process the show reduces McPherson’s remarkable life to a cliché-bestrewn fable about the wages of fame…“Scandalous” isn’t so much scandalously bad as it is generic and dull…Ms. Carmello, a gloriously gifted singing actress, has never managed to snag a star-making breakout role on Broadway — not all that surprising in these difficult days for musical theater. Sister Aimee certainly provides plenty of opportunities for Ms. Carmello to thrill us with the purity and power of her voice. She leads a few rousing come-to-Jesus gospel-tinged numbers with bright-beaming intensity. She delivers the climactic soul-baring ballad with plenty of emotional heat. What she cannot do — no singer without the power of miracle could — is bring distinction to songs that never rise above the serviceable.