Figuring out the key of a song by ear (sense of key training)

1. Choose the key of the song in Singing Pitch Trainer
2. Singing Pitch Trainer will grey out the non key notes, to make it easy to play the relevant notes in this key
3. Play a line from the song, and sing that line, and at the end of the line, find the last note on the piano.
4. From that note, sing the scale down (descending) till you reach the key note (A major means the key note is A). This will strengthen your sense of what the key or ‘root’ or ‘tonic’ note sounds like (all mean the same thing).
5. Repeat step four, but this time sing ascending (up), instead of descending (up) till you reach the key note.
6. Repeat with a different line of the song.
7. Repeat with all the songs from all the keys.
8. Repeat, Repeat, REPEAT! and it will get easier to identify the tonic/key/root note.
9. You can also repeat this process for the relative minor key. You will see it listed in SPT (Singing Pitch Trainer) next to the major name. This example is F#minor, pictured above.
Blackstreet – No Diggity (Key A Major)
Kelly Clarkson & Justin Guarini – Timeless (Key Bb Major)
Justin Timberlake – Cry Me A River (Key B Major)
Boyz II Men & Brian McKnight – Let It Snow (Key C Major)
Stevie Wonder – Ribbon In The Sky (Key Db Major)
Ed Sheeran – Thinkin Out Loud (Key D Major)
Az Yet – Last Night (Key Eb Major)
Sam Smith & John Legend – Lay Me Down Key E Major)
Beyonce – Dangerously In Love (Key F Major)
Ariana Grande – God Is A Woman (Key Gb Major)
Maxwell – Whenever, Wherever, Whatever (Key G Major)
John Legend – All of Me (Key Ab Major)