illustrator and figma should be mainly used to create illustrations for the music app

Illustrations are important skills especially if you are thinking of working for fin-tech companies as data visualisation is important for them

the essence of illustration

to clarify

to show clearly

to provide with visual features to get context

Illustrations in ui should be ;

meaningful

attractive

not overloading the screen or page

harmonic and corresponding with other ui design elements

types of illustrations ;

mascots and characters example mailchimp monkey and github cat octopus

badge collection ranking system with unique illustrative icons might be nice add on for your apps and website design

hyper realistic illustrations

hand drawn illustrations