This was a special full hour episode with two parts: an unusual "locked room" story with Brian and Stewie, and a collection of the show's musical numbers.  Ostensibly this was done to celebrate the show's 150th episode, although Wikipedia labels this as the show's 147th episode.  That's confusing.  There was also a tie-in to a "Fox Rocks" theme night, but since I watch everything on Hulu I wasn't aware of this until I read about it later.  (This does explain the Simpsons' "Tik Tok" intro, which I thought was as delightful as it was unexpected.)

In the first part of the episode, Brian and Stewie get locked in a bank vault.  They are stuck there together for two days (or something like it).  Please to be overlooking the logical problems with this plot.  For one thing, I'm pretty sure the bank checks before it slams the door shut on the safety deposit box vault.  For another thing, a baby would probably have died of dehydration by the time the vault was opened - and scotch would only have made it worse.

Pshaw.  I wave away your objections, and insert my own.  I get the feeling Family Guy is spending a lot of time trying to be everything to everybody.  The first act is gross-out humor, the second act is slapstick, and the third act is solemn heartfelt character building stuff.  

Of these, the gross-out sequence is the most effective, which makes sense, because that's the easiest to pull off.  The slapstick was adequate, as you might expect from a show of its caliber and history.  The heartfelt stuff was far too earnest and direct, and is the kind of thing that's done far better by more nuanced shows like The Venture Brothers and South Park.

But there were things that I liked about the episode.  I like the way that Stewie's schtick has gone from "must kill Lois" to this ridiculously archaic and adult thing, like his use of the term "porte-cochere."  

Most of all I liked that they broke out of their usual formula.  And if it wasn't completely successful, it's still a success for having tried it.  I've always felt that Family Guy is a show with a lot of untapped potential, and I would really like to see everyone involved push the show in different, weird directions like this.  I was particularly impressed by the way their conversations would weave in and out of each other, and a thread that got dropped in one part would be picked up and pulled in a different direction later.

Then came the musical numbers, which were as entertaining as always.  I really enjoyed Peter's previously-unaired musical number, which was stolen from the Jerry Lewis film "The Errand Boy."  (I enjoyed it a lot more before I looked up the original on YouTube and found out they weren't kidding about saying they stole it.  It's a gesture-for-gesture exact copy of Lewis' pantomime.  Weird.)

Next we had repeats of show classics included "You've Got A Lot To See" and the inestimable "Shipoopi."  Can you get too much "Shipoopi"?  I think not.