Hacker News on 21 February 2016

• AI generated music to improve focus, relaxation and sleep
• The Apple letter to customers couldn't happen under proposed UK law
• Understanding Git for real by exploring the .git directory
• What’s Next in Computing?
• PeerTweet – Decentralized feeds using BitTorrent's DHT network
• CoeLux: Artificial Sunlight That’s Real Enough to Trick Your Camera and Brain
• Washington Should Prepare for Saudi Arabia's Collapse
• Discover Flask
• LG G5 modular phone: Hi-Fi DAC, battery slide out, connection interface
• Vapor: a type-safe web framework for Swift