Well they can be singing a duet.
A "duo", what they preform is then called a "duet" :)
What is a pair off singers called ? its only 3 letter but the last letter or the first is a D so plz answer my question?.....
Duet
Paul & Paula
Duo
Two singers are a duo.They might sing a duet, a musical composition for two performers.
people who can croon a tune
A Duet
choirmaster
Orchestras
Octet.
Choir, harmony