What is a whole step below D flat​

Which of the following lists of ordered pairs is a function?

How is pop music related to popular music? what theme does pop music typically discuss in the lyrics? why do you think this theme relates so much to lots of different types of listeners? describe one pop song that uses this theme. what is disco? when did it develop, and what characteristics set it apart from other genres of popular music? what was the british invasion? which famous group was a part of this movement? what impact did the group have on pop music? what is a boy band? what are some characteristics of a boy band?

Why did david smith burnish the surface of his work cubi xix?