The Cat Piano

The Cat Piano is a short animated film (running about eight minutes) about a New York-style city inhabited by anthropomorphic cats. The narration, written by Eddie White in the style of 1950s beat poetry and read by Nick Cave, describes the plight of a lonely writer who falls in love with a beautiful singer. The mass abduction of all the singing cats and the resulting mass hysteria causes the town to fall apart. After struggling with despair, the writer sets out to rescue his beloved.

It can be watched in its entirety here.

Tropes used in The Cat Piano include:

Art Shift: The cats suddenly stop being anthropomorphic when they attack the mad human in the lighthouse.
Cast of Snowflakes: Even background characters have unique designs
Cat Concerto: This anthropomorphic variation has them as 1950s lounge singers and beat poets.
City with No Name
Cold-Blooded Torture: A human drives nails into cats' tails to make them scream.
Does This Remind You of Anything?: The Nice Guy who saves the fascinating singer from a sadistic sociopath shows clear references to Blue Velvet.
Driven to Suicide: At one point, the protagonist mimicks the act of shooting himself.
Earn Your Happy Ending
Film Noir: 95% pure Film Noir.
The Fifties: The aesthetic is largely derived from Film Noir and stars a Beatnik cat.
Not So Funny Background Event: One scene had the narrator poetically telling "There was a hole in my heart and everything fell out of it...", while the background animation features another cat getting messily stabbed in the heart during a brawl.
Furry Female Mane
Hidden in Plain Sight: The lighthouse, which is the highest and most noticeable of buildings in the entire city, stands isolated on a small island in the bight and serves the mad human as a hideout. At first, when the kidnappings start, the light goes out, and when the piano starts playing, a red light goes on instead. This is when the poet takes action and storms the lighthouse with a mob of citizens. Nevertheless, the trope is justified as the tower is heavily symbolical rather than anything else.
Humans Are the Real Monsters
Instrument of Murder
Nameless Narrative
Narrative Poem: He is recording the events, and he narrates the whole thing as he types it.
Ominous Pipe Organ: Made of cats.
Private Eye Monologue: Averted. Although this is a Film Noir, the narrator is neither a private detective nor does he narrate in an appropriate "Private Eye" manner. He narrates an epic beat poem.
Sliding Scale of Shiny Versus Gritty: The female singer is pure white with green eyes and glows visibly in the blue-toned atmosphere.
Torches and Pitchforks: The mob of angered cat citizens that is led by the writer to the lighthouse. This is, however, notably done without torches or pitchforks to keep the gritty atmosphere. Instead, the cats pounce at the mad human and claw him violently before he manages to fall out a window to his death.
You Gotta Have Blue Fur