Panel 1: Ah, so she's gone to Grampa for...solace? Counsel? Obligatory stay-in-the-will visit?
Panel 2: As others have said, April must not have had much confidence to begin with, or loved music very much.
Panel 3: Wow, he's agitated! Two exclamation points after his question mark! And I will admit that someone who's been in bands off and on for years (check the collections; I think Grampa's musical efforts go back to post-WWII) saying that music should be for fun carries more weight than Laura or John saying it.
Also, April's right arm and leg seem very bendy.
Panel 4: Ack! An old person is going to go on and on about something! I suddenly have to be somewhere else five minutes ago! And I love the visual shorthand of the pointing finger.
Panel 5: Hm. Does that mean that his one remark is enough to restore her interest in the band? Or is it just a polite way of saying cutting him off? ETA: Judging by April's expression in panel 4, I think that's it. At any rate, Grampa looks very disappointed that he didn't get to give his speech!