This song by Elvis Presley is in C.
The G7 at the end of Part 3b is to bring the song back to Part 1a, i.e., you only play the G7 if you repeat the song.

These are the “cheat” chords I played…
Part 1a: CM7 - Em - Am
Part 1b: C - C7 - F
Part 1c: G7 - G7/D - G7 - Dm7
Part 1d: Dm7/G - CM7
Part 2a: C7 - F
Part 2b: D7 - G7
Part 3a: CM7 - Em - Dm7 - D7
Part 3b: Dm7 - G7 - CM7 (- G7)

Tags: are you lonesome tonight, cheats, chords, easy, easy play, elvis presley, how to play, karaoke, piano, progressions, shortcuts, simplified, singalong, tabs

This song by Ray Charles and Willie Nelson begins in F, and later modulated to F#.
Notice that Part 3 and Part 4 are played in F#.
The C#7 at the end of Part 2b is a chord to bring the key to F#.

These are the “cheat” chords I played…
Part 1: F - C7 - C7 - F
Part 2a: F - F7 - Bb - (Eb/Bb - Bb)
Part 2b: Bb - F - C7 - F - C#7
Part 3: F# - C#7 - C#7 - F#
Part 4a: F# - F#7 - B - (E/B - B)
Part 4b: B - F# - C#7 - F#

Tags: cheats, chords, easy, easy play, how to play, karaoke, piano, progressions, ray charles, seven spanish angels, shortcuts, simplified, singalong, tabs, willie nelson

This song by Foreigner is in F#.

These are the “cheat” chords I played…
Part 1: D#m7 - C#/F - F# - B - D#m7
Part 2a: F# - G#m7 - C#/G# - G#m7
Part 2b: C#/G# - G#m7 (repeat several times)
Part 2c: B - F#/A# - G#m7 - F# - B/C#
Part 3: F# - C# - G#m7 - C#

Tags: cheats, chords, easy, easy play, foreigner, how to play, i want to know what love is, karaoke, piano, progressions, shortcuts, simplified, singalong, tabs

This song by Ikimono Gakari is in E.

These are the “cheat” chords I played…
Part 1a: E - A2 - B4 - E - B/D# - C#m7 - A2 - F#m7 - B4 - B
Part 1b: E - A2 - B4 - E - B/D# - C#m7 - A2 - F#m7 - B4 - E
Part 2a: C#m7 - A2 - E - G#4 - G#
Part 2b: C#m7 - A2 - F#m7 - B4 - B
Part 2c: C#m7 - F#m7 - B4 - B
Part 3: A2 - E - B - C#m7

Tags: cheats, easy, easy play, how to play, ikimono gakari, karaoke, koisuru otome, progressions, shortcuts, simplified, singalong, tabs

擱淺 by 周杰倫

This song by Jay Chou is in F, except the interlude (Part 4), which is in Ab.

These are the “cheat” chords I played…
Part 1: F - A7 - Dm7 - Dm7/C - Bb - Am7 - Dm7 - Gm7 - Bb/C - C
Part 2: Em7 - A7 - Dm7 - Dm/C - G7/B - Bb/C - C - F/A
Part 3a: Bb - C/Bb - Am7 - Dm7 - Gm7 - Bb/C - F - F/A
Part 3b: Bb - C/Bb - A4 - A7/C# - Dm7 - Gm7 - Bb/C - F
Part 4: Ab - Eb - C/E - Fm7 - Db - Db/Eb - Eb - Bb/C - C

Tags: cheats, chords, easy, easy play, how to play, jay chou, karaoke, piano, progressions, shortcuts, simplified, singalong, tabs, 周杰倫, 擱淺