This cartoon is a bit different in the beginning... after the opening strains of Popeye's theme in the credits, we get a rendition of "Rock-a-Bye Baby," accented with what sound like either gunshots or just a slam! Of course, after the credits, Popeye's singing his theme song, but this time he's rocking a stroller, which has a baby sleeping in it (I don't believe it's supposed to be Swee'pea, as it doesn't look like him at all). Popeye stretches an ear over the child to be sure it's asleep, and is satisfied... until he hears a harp being played down the street (by Harpo Marx, no less!). Popeye tries to talk Harpo into not playing, but isn't successful, and the baby opens an eye, and then starts crying! Popeye smacks Harpo so hard he flips over 360 degrees, only to end up with a halo, and floating up towards heaven, playing the harp.
Of course, now Popeye has to sooth the baby back to sleep, which he tries to, but then the baby pops Popeye in the jaw, sending his pipe flying! This happens another time, and then Popeye sets the baby back in the stroller with a ukelele, which the baby uses to tune up his crying, and then plays the uke, interjecting cries as he plays! Popeye can't stand this, and takes the uke from the baby, playing it himself and singing himself (a different song, "Go to Sleep, My Baby," and without his usual voice). The baby gets Popeye's pipe and starts smoking it as Popeye continues to sing (occasionally getting to his normal voice). The baby's enjoying the pipe, and then it falls asleep, Popeye apparently unaware it was his pipe that did it!
Popeye starts gently pushing it down the street, but as he passes by a music school, the sound of the instruments tuning up threaten to wake the infant, so Popeye goes inside and tries to silence the musicians, but of course he has to destroy the the instruments (a cello gets Transformation Punched into four violins at one point) in order to get any silence, knocking out the musicians, too!
Later, down at the waterfront, an ocean liner blows its whistle, so Popeye swims out to it and pulls the whole ship beneath the water, shaking the water off himself like a dog when he gets back to shore. Later, walking down the street, there's a radio playing loudly at a radio store, which Popeye punches so hard that his punch goes back to the radio station and knocks out the performer! The next impediment to keeping the baby asleep is construction on a building, with the workers banging away on the girders, so Popeye starts bashing them away, sending the building falling like a house of cards! However, since Popeye's left the stroller in the middle of an intersection, now there's cars stopped all around the baby, honking their horns! Popeye tries to silence them by shushing, but it doesn't work, so it's spinach time!
Now, this was an odd one -- it's only the seventh cartoon in the series, but it's already breaking away from the usual formula of the Popeye series -- no Olive Oyl, no Bluto (or any other physical threat to anyone)... unless we assume that the baby is supposed to be Swee'pea (and I somehow recall that the Fleischers didn't always get him on model, but I could be misremembering), there's no other member of Popeye's comic strip cast in this at all! We don't know why Popeye's pushing this baby around (although we can presume that he's agreed to babysit out of the goodness of his heart, because at his very core, Popeye is a good man, even if his temper sometimes gets the best of him), we can only marvel at the extremes he goes to in order to try to keep it quiet so the baby can sleep -- this is something that those of us who are parents can probably appreciate!
Having said that, it would've been nice if it had opened with Popeye going to see Olive, and her saying she was babysitting this child, and could Popeye watch him while she goes to the market for a few minutes, and then lead into all this, with Popeye being admonished that the baby must get his nap (I believe this set-up gets used later in the series). I'm also rather confused as to why, when Popeye didn't need his spinach to pull an ocean liner under the water, he needed it to smash some cars up -- this is one of the weaknesses with the earlier cartoons in the series, that inconsistency so far as Popeye's strength goes. Certainly, even before eating his spinach, he should be plenty strong -- stronger than an ordinary man could be -- so when he eats the spinach, he should be doing way bigger feats! If I had to guess, I would have to posit that when this cartoon was being made, someone realized it was almost over, and they hadn't had the spinach stunt yet, so instead of re-arranging things so that the ocean liner stunt was the final one, they just used the last stunt Popeye was to perform.
Of course, it also wouldn't surprise me if the whole thing was set-up so that when the pin dropped, that woke up the baby, not all the other stuff. Anyway, given all the above, out of five cans of spinach, I'll have to rate this one... three cans!