Now, to get back to the dislike for Michael’s taking up the trumpet as a hobby, I'd like to fast-forward a bit to John and Elly’s hope that April’s band would disintegrate owing to lack of interest. The way they saw it, once she realized that music was meant as a means for the family to get together and sing along together without the distraction of threatening strangers that threaten that togetherness by raising the threat that people might think that they don’t owe their parents for making the sacrifice of feeding, clothing and housing them, the risk of her leaving the family and living a life without her ‘loving’ parents as its focus was minimized. Unlike Eva Warzone and Luis Refugee who could be relied on to tell April that her parents had ‘her’ (read 'their’) best interests at heart, Evil Becky had the dangerous, evil idea that catering to the whims, ignorances, greeds, needs and prejudices of Elly and John Patterson need not be the be-all and end-all of April’s life. As long as the band existed, the right John and Elly had to April’s horses was in danger so it had to join the pee-wee hockey team in the rubbish bin of bad ideas that expose John and Elly to the unacceptable risk of having someone tell them to their faces that they’re self-absorbed vermin who want a reward for basic decency.
When you combine all of this with the passive-aggressive commentary on how unmotivated Aaron looked in the most recent notes, it’s easy to see that howtheduck is right on the money when he speculated that Lynn was dead set against Aaron playing in his school band. What seems to have happened is that Aaron’s primary caregiver Ruth Johnston drew upon her experience as a retired school teacher and floated the idea as a means of making sure that Aaron had some means of fitting in with his new classmates instead of whatever stupid, wrong-headed idea his biological (but not real) mother might have come up with.
What that idea might be is hinted at in articles he and Katie wrote for her collections. The picture that emerges is that Lynn was and is still so in love with this whole “creative trance which requires total isolation from her surroundings” nonsense that she’s allowed herself to become a complete and utter incompetent in her daily life. Not only can she not prepare her own food or clean her own house or handle her personal finances, she was never really involved in her biological children’s lives and didn’t want them to do anything to bring her back to a reality she saw as a minefield of oppression and humiliation. This means that we get a situation where a self-absorbed idiot parent sabotages every last attempt the child might make to have an identity that isn't related to Mommy or Daddy only to turn around and wonder why the child feels as if she doesn't belong any where.
What I take away from all of this is the idea that the reason the Pattersons aren’t allowed hobbies that might take them outside the safety of home is that Lynn clearly doesn’t much like any outside interests her family might have that don’t allow her to be the real center of attention or might require her to engage in a real world that she doesn’t dominate. Pee-wee hockey, Aaron’s school band, Rod’s charity work, Rod’s career as a dentist, none of those things allow her to parade around yelling “Look at MEEEEE!!!!!!!!!” so they’re all worthless. After all, outside interests mean that people lose sight of what’s really important: devoting their free time to making sure that a domineering, demanding, selfish tyrant who will not do things for herself because exploiting other people is easier is taken care of.