I've seen several episodes of Phineas and Ferb now and even though I tried to keep an open mind, one thing has become painfully obvious.
It seems this cartoon is specifically engineered to have the lead characters sing a song at the drop of a hat.
While that works for a feature length movie, it's not a good idea to incorporate that into an 11 minute episode!
At a rough guess, you're loosing approximately half the episode because somebody is singing about something or other.
And they're doing it in a music video too.
The only songs I can think of that supported the story were Busted (Candace and Vanessa), I'm Me+Not So Bad A Dad (Vanessa).
The rest of them were just eye candy, something to dazzle the viewer.
You could most likely express the same sentiment in a line of dialogue.
For example, Isabella spends 2 minutes singing about what she'd like as a birthday gift when she could just say it in one line and then the show could continue on.
I think we understand what she wants after she says it once, yet she's said it 20 times over by the time the song is done.
The worst one I've seen is Doofensmirtz's exercise montage, which is just him and Perry doing workout moves to music.
There's absolutely nothing happening in the song that advances the story, it's just a lot of special effects.
Which has now got me wondering, do the creators of the show have the ability to fill an entire episode with story based content if they keep dropping in a song during the show?
Given how heavily they emphasize the musical aspect of this show makes me think it was not intended to be a serious cartoon at all, just a reason to justify writing songs and making music videos.