The plot itself is pleasantly simple enough for us to follow without thinking too hard about it, allowing us to just empty our minds with the laughs involved. Tom's the pianist of an apparently major concerto and Jerry's been living in the piano. Annoyed with Tom's work on his home, he intends to get back. It's just that. It's a departure from the cat and mouse chase they had working for them, but it's the same theme of their animosity and a refreshing template for them to base it off of. From the beginning, they subtly let you know this is a comedy, from Tom's brief wardrobe malfunction.
Then begins the fun. While points of the animation do not sync as well with the music as several other points do, the music provides a very nice rhythm for the physical show the two do so well, having them bounce along to the sound. It also provides energy and intensity to what's going on. It doesn't forget the squeaky cartoon noises of things like scissors, slamming the keys' cover and the suit falling down. They just all give the spotlight to the great music, every once in a while showing up to do their job.
This time, the advantageous mouse hole is the inner workings of the piano. Some classic gags exist., like the entire pancaking of body parts, but for the most part it revolves around the usage of the keys or the inner hammers on the strings of the pianos, usually bouncing Jerry up and around.
Eventually Jerry takes the upper hand and completely tires Tom out to the point of Tom's suit falling apart. A usual victory for the little mouse concludes the short, as he takes Tom's bow for him.
Based on the style, animation, shot choice and use of sound, I give this an 8/10. It's enjoyable every now and again to remember the fundamentals of silent comedy, but it's not totally innovative save for its use of music as humor.
But don't just take my word for it. Watch the damn thing. Now.