Numbers in the text and what they refer to:

• 2012: Beyoncé gave birth to a daughter in 2012.
• A billion: The Beatles have sold more than a billion records.
• Hundreds: Madonna has had hundreds of hits.
• 25: A singer or a band must wait 25 years from their first hit before they can enter the US Rock and Roll Hall of Fame.
• 50: In the past 50 years The Beatles have sold more than a billion records.
• 1960s: The Beatles became famous in the 1960s.
• 1981: Beyoncé was born in Texas in 1981.
• 2000: Not specified directly in the text, but implies the start of the new millennium.
• 2008: Madonna entered the US Rock and Roll Hall of Fame and Beyoncé married her long-time sweetheart.
• 2017: Beyoncé gave birth to a pair of twins (a boy and a girl) in 2017.