Readers reply: If an alien asked you: ‘What is music?’ what would you play for them?

The long-running series in which readers answer other readers’ questions comes up with an epic extraterrestrial playlist for Earth’s first contact from beyond the stars

• This week’s new question: Experts say we should use passkeys, but can a smartphone PIN really be safer than a password?

If an alien landed and asked you: “What is this thing you call music?” what would you play for them? And why? Heather, Kent

Send new questions to nq@theguardian.com.