Angry Birds is a puzzle video game developed by the Finland-based Rovio Mobile, released in December of 2009.c Its catchy theme song was written by Finnish composer, Ari Pulkkinen.c The song is in the key of E minor and is based around the following chord:

How to Play the E Minor Chord

This instrumental theme song has an intro and three sections, following this pattern:

• Intro
• A Section
• B Section
• C Section

Here's a walkthrough of what you'll do in the video:

For the intro, your left hand starts on E and then moves to B, G and F# while your right hand plays the melody. 

During the first section, your left hand alternates between an E and B note while your right hand plays the melody. In the second section, your left hand will instead switch between the B and E notes. 

The third section contains minor second intervals (two notes that are next to each other on the piano). These dissonant intervals cleverly capture the birds' frustration. The song ends with a big E minor chord.