The Associated Press obituary for Mitch Miller includes this highly questionable tidbit:
Miller's square reputation in the post-rock era brought his name and music to unexpected places… During Queen's nonsensical camp classic, "Bohemian Rhapsody," the group chants "Mitch MILL-uh!" as if to affirm the song's absurdity.
Surely that's a mondegreen. The AP would have been well-served to consult Am I Right or Kiss This Guy, online repositories of misheard lyrics. It's not "Mitch Miller" that Queen is singing, but bismillah, the formulaic utterance in Classical Arabic that introduces each sura (chapter) of the Qur'an. (It means "In the name of God"; the full formula is bismi-llāhi r-raḥmāni r-raḥīm, "In the name of God, Most Gracious, Most Merciful.")
I've read that the bismillah in "Bohemian Rhapsody" is a nod to Freddie Mercury's upbringing in majority-Muslim Zanzibar. (Mercury himself was from Zanzibar's Parsi community, Zoroastrians hailing from India.) That would make sense, as a remembered snatch of Qur'anic Arabic mixed in with the song's other odd refrains (such as the pseudo-operatic "Scaramouche, Scaramouche, will you do the fandango?"). It's certainly a lot more plausible than Mitch Miller making an unexpected appearance. But judge for yourself:
(Hat tip to Phillip Blanchard of Testy Copy Editors, who adds, "AP reported this canard as if to affirm its own absurdity.")
[Update #1: Blanchard points out that the AP later corrected the obituary by removing the bit about "Bohemian Rhapsody."]
[Update #2: Nijma makes a pertinent point in the comments below:
Bismillah, along with the Ta’awwudh, is used to fend off supernatural beings like devils and jinn. In the song, the soloist tries to escape, "Let me go, let me go, bismillah, bismillah," while the chorus sings the part of the devil, "No I will not let you go."