In the same IG post, Raymund clarifies that he is not part or knows anyone in production of the musical, permission was already settled by the publisher and they don’t need Raymund any member of the Eraserhead’s permission. Raymund cannot come to the musical gala, since he has (two) prior commitments to attend to.
“Ang El Bimbo” is one of Eraserhead’s greatest hit and where the musical is based. I’ve embedded the music video of the song below.