You are right that songs are buttons pressed in a certain order. However in the vast vast majority of cases, a song will not use all possible buttons on the piano. It will instead use a specific selection of buttons. This selection is what defines the key of the song.
An analogy with English would be with usage of letters. If you write text with only words that start with F, or text with only words that don't contain E, etc., you can create many different "flavors" of text that will feel different. This is similar to what's happening when a song uses a specific selection of notes for its key.
letao12 t1_jd9izsx wrote
Reply to ELI5: How can songs be in a certain key? (And a few more questions about music) by Glum-Airport-4701
You are right that songs are buttons pressed in a certain order. However in the vast vast majority of cases, a song will not use all possible buttons on the piano. It will instead use a specific selection of buttons. This selection is what defines the key of the song.
An analogy with English would be with usage of letters. If you write text with only words that start with F, or text with only words that don't contain E, etc., you can create many different "flavors" of text that will feel different. This is similar to what's happening when a song uses a specific selection of notes for its key.
This video covers a lot of the basics, you might find it helpful: https://youtu.be/28ipYr_aKb8