Katydids and cicadas songs sound buzzy, raspy, or whiney, because their carrier frequencies are less pure and are higher than those of crickets. Cicadas call almost exclusively during daylight hours and at dusk, usually from trees and shrubs, whereas most katydids call only at night and many are not resticted to woody vegetation.
Cicadas are plant-juice-sucking Homopterans (along with leafhoppers, aphids, and scale insects), while crickets and katydids have chewing mouthparts……Katydids are actually grouped into the long-horned grasshopper family.
Cicada on my front porch
Katydid from internet fileA lucust from internet file
All I know is that this is the time of year when cicadas, katydids, locusts and grasshoppers fill the evening with thier songs. In the neck of the woods where I currently live, thier song is so loud it is hard to think! They have something to sing about I suppose.
I've also learned calling a cicada a katydid is like calling a Texan a Californian or a Presbyterian a Baptist!