There's nothing really 'faithful' about THE SOUND OF MUSIC, especially if you add in the Richard Rodgers lyrics of the songs which were penned for the film.
By all accounts the actual Maria was a deeply faith-driven woman, but a faithful Catholic would never sing a lyric like "I Have Confidence," which places confidence in herself, in "confidence alone." I don't think Hammerstein II would have allowed that lyric to pass...
... much less the deep karmic philosophy of "Something Good," where Maria imagines that the good deeds she'd performed in the past had brought her a blessing of new love. Such ideas fly in the face of the concept of unmerited grace -- that God blesses you simply because he loves you, not because you deserve it.
All this to say, I have no issue with a public school performing CHILDREN OF EDEN any more than a performance of FIDDLER ON THE ROOF. I would think that any atheist would be perfectly happy to see the book of Genesis reduced to a mere musical.