Heard It All vs Key Lens

Think you've heard them all? Heard It All invites you to explore every Billboard Hot 100 #1 song — from the chart’s inception in 1958 to today’s biggest hits. This isn’t just a checklist. It’s an immersive, nostalgic journey through music history. • Dive deep into each song Every #1 hit includes artist images, song artwork, and detailed info — including songwriters, album details, and links to explore more on Wikipedia. • Play it your way Listen to each song instantly on your favorite platform — Apple Music, Spotify, Amazon Music, or YouTube. No subscription? No problem — YouTube links are always free to view. Playlists for all #1 hits and filtered by decade are included for all music services. • Unlock fun (and mysterious) badges Badges are at the heart of the app. Earn achievements as you go — from milestones like “1970s Completed” to hidden gems like "Shaken, Not Stirred" (James Bond #1s) or "Long Timer" (epic-length hits). Some badges you’ll earn without even trying. Others you’ll have to uncover. • Feeling spontaneous? Tap into the Random Song feature to discover a #1 you’ve never heard before — a perfect way to explore forgotten hits or unexpected chart-toppers. • Powerful search and filters Find songs by year, artist, genre, decade, duets, one-hit wonders, and more. Whether you're reliving a favorite era or tracking down something obscure, it’s all at your fingertips. Whether you’re revisiting the soundtrack of your life or discovering classics for the first time, Heard It All helps you experience the Billboard #1s like never before.

Start with a scale. Every chord, note, and progression in the app stays locked to the key you pick. Explore common chord progressions or build your own! Extensive options for voicings, inversions, extensions, borrowed chords, alternate bass notes, and more. Learn to play your chord progression on piano! Easy to read, color coded piano diagrams make playing your chords on a real piano easy.