when bleeding gums murphy dies, it just so happens that bart had won a $500 lawsuit against krusty, instead of buying what he wants he buys lisa, bleeding gums album, to support her through the tough time.
Also...hmm i had another one, maybe when bart sells his soul, lisa goes out of her way to get it back for him.
oh heres the other one
the story behind lisa's sax, homer wants an air conditionor and lisa is going to be accepted at a great private school but the simpsons cant afford it. To enrich her life with the money they have, homer gives up their air conditioner money in order for lisa to get a sax.
when lisa thinks she is losing her mind and going to become another dumb simpson, homer gets all the simpson relatives together to show her that they can succeed...all are dumb fools, but then they talk to the woman of the simpson family and they are all doctors, lawyers, etc...helping lisa no longer lose confidence