Simplify the following text for a Grade 6 native English-speaking person.
Original: In the 1960s and 1970s the quena was used by several Nueva CanciÃ n musicians , this use was in most cases for particular songs and not as an standard instrument but some groups such as Illapu have used it regularly .
Simplified: In the 1960s and 1970s the quena was used by several Nueva CanciÃ n musicians . Some groups such as Illapu have used it regularly .