Task: Question Answering
Input (English): Passage: In 2006, Beyoncé introduced her all-female tour band Suga Mama (also the name of a song in B'Day) which includes bassists, drummers, guitarists, horn players, keyboardists and percussionists. Her background singers, The Mamas, consist of Montina Cooper-Donnell, Crystal Collins and Tiffany Moniqué Riddick. They made their debut appearance at the 2006 BET Awards and re-appeared in the music videos for "Irreplaceable" and "Green Light". The band have supported Beyoncé in most subsequent live performances, including her 2007 concert tour The Beyoncé Experience, 2009–2010 I Am... World Tour and 2013–2014 The Mrs. Carter Show World Tour. Question: What are Beyoncé's backup singers called?
Output (English): The Mamas