If you enjoyed Gwyneth Paltrow’s sensational appearance on “Glee” last night as the coolest substitute teacher ever, rockin’ not just a (sanitized) version of what the Cee-Lo song they call “Forget You” (fortunately, the lyric “If I’d a been richa, I’d still be witcha” survives) but “Conjunction Function” from Schoolhouse Rock, then be sure to take a look at this neglected gem, her performance with Huey Lewis in “Duets.” The movie is uneven but with a lot of heart, and Gwyneth, directed by her late father, Bruce Paltrow, is luminous and sings like a dream.

She’ll be singing again next month in her new film, “Country Strong,” as a country music star just out of rehab.