Radio cassettes and CD players are one of the earliest forms of portable music players. They were very popular in the ’90s and early 2000s, but their popularity has since diminished.

Radio cassette players were the first type of portable music player. They were popular in the ’90s and early 2000s. They worked by playing cassettes that had music recorded on them.

CD players are a newer type of portable music player. They were popular in the late ’90s and 2000s. They work by playing CDs, which are discs that have music recorded on them.

Both radio cassette players and …