Sure! Below is a sample response to Mark's email in English, adhering to proper letter formatting and answering his three questions:
From: Russian_friend@mail.ru
To: Mark@mail.uk
Subject: Music
Dear Mark,
Thank you for your email! I appreciate your invitation to the concert, but I'm more into pop music. If I had to choose, I would love to see Ed Sheeran in concert; his songs are amazing! I actually play the guitar, which allows me to enjoy music even more.
What about you? Do you like any specific genres? I look forward to hearing from you soon!
Best wishes,
[Your Name]
You can replace "[Your Name]" with your own name or leave it out if you'd like. The letter is concise, friendly, and sticks to the word limit you specified.