there_i_ruined_it is an Instagram account that just posts hilariously terrible musical mashups. Case-in-point: this recent re-imagining of Sir-Mix-A-Lot's classic "Baby Got Back," performed in the style of an Elvis Presley song.
To be fair, this is less of a "mashup" and more of just a cover song with AI-generated vocals. But … damn, it's perfect to the form.
And of course, for the non-embed crowd: