Back Alley Oproar

Back Alley Oproar is a 1957 short animated by Alexander Williamsburg.

Plot
Elmer and Mandrilla is ready for bedtime, but Sylvester has other plans as he starts singing on the fence in Elmer's backyard. A series of gags play out, as Elmer tries everything up his sleeve to get rid of that unwanted pest. Elmer eventually confronts Sylvester, but before Elmer can blast him with his shotgun, Sylvester sings a sweet, gentle lullaby to ease him to dreams. However, this doesn't last, and the insanity continues…

Elmer eventually dies from explosives from his attempts to get rid of Sylvester. He winds up in Heaven, as an angel on a cloud. Momentarily he thinks he will finally get some peace and quiet. However, the spirits of Sylvester's nine lives continue to sing as they ascend around him, each with a numeral on his back (there are actually more like 18 Sylvester's depicted overall), singing the sextet from "Lucia di Lammermoor". One of them even took Elmer's halo. The exasperated Elmer dives off his cloud and a crash is heard.