While Elly and John travel the same path, what April will only have just now figured out is that they came there by different roads. While I'll get to John next, I'd like to remind you of Elly's real problem: she does not know what music is for. As history teaches us, the reason that she systematically destroyed Mike's interest in the subject was because she assumed that the point of his accomplishing things was for her to be praised for dragging him across the finish line. She clearly had an image in her mind of her being praised for his hard work and skill because she's hardwired to see things as an opportunity to be flattered and his wanting to not take things as deadly seriously as she did was seen as his wanting her to die an anonymous death. Since no one is going to praise a ghost who won't support her daughter because she hates the genre because it's popular and also because the lyrics preach the dangerous message "parents don't actually know everything", she can't see the point of the band.
We also have to contend with the fact that she tends to regard parenting itself as being this horrible imposition that fills her with anger at the time lost and hatred for the dependent children who distract her from her alleged destiny and the awful people who use the evil phrase "moral obligation" when telling her that only chickensh*t people wish there was a return bin for children when one is bored of them. Since the band is an inconvenience that reminds her that she can't simply declare victory and say that she's done being a parent just because it's a minor difficulty, she's hoping and praying that Becky humiliates April into admitting that anything that doesn't mesh with the family politics is bad.