Because of this the rules were quickly changed so that cassette singles were allowed.
Originally, most cassette singles were released in a cardboard sleeve that slipped over the outside of the release.
In some markets, cassette singles generally used the same packaging as standard cassettes, a plastic box with a paper insert.
They had put out a number of cassette singles and demo records.
And cassette singles of five recent songs by the New Kids have sold 2.5 million copies.
More than 45 million cassette singles were shipped to stores in the first half of the year, a 39.3 percent increase from 1989.
Music videos and cassette singles are booming in the music business.
There's something new in record stores - cassette singles.
Two kinds of cassette singles have been introduced.
Between 35 and 50 songs have been released as cassette singles.