The title tells you that this is clearly intented to be about Bing Crosby, although the character doesn't have Bing's face, as you would see in later Warner Brothers cartoons. The high point is the comic song "Bingo Crosbyana" that pokes fun at Bing's effect on women as a crooner.
Bing sued Warner Brothers over his portrayal in the cartoon as a coward. As others have noted, without his actual face being shown, Bing didn't have a case against them, despite his character singing a couple of bubba ba boos.
What makes the cartoon interesting is the comic spin that the 'hero' turns out to be a coward, and that the other male flies, emasculated by the crooner fly, become the heroes that defeat the spider. Contrast this with the countless other insect or spider and fly cartoons such as "The Cobweb Hotel" (1936) by Max Fleisher.
I'd give it a 5 for the song and the spin. Note: You can find this cartoon on the DVD of the Fred Astaire-Ginger Rogers film "Swing Time" (1936).