Piano chords · Pop heartbeat
I Don’t Know Why: piano accompaniment sheet music
Written by Fred E. Ahlert
- Bb major
- 4/4
- 90 BPM
- VI7–ii–V7–I loop
- 1931
- Easy
I Don’t Know Why written out as piano music: the VI7 – ii – V7 – I loop in Bb major for both hands, with chord names and finger numbers. Press play and follow the cursor. The left hand plays lazy footsteps (root bass · 1 · 3 · 4), and the right hand sings the tune.
I Don’t Know Why chord chart
The loop once round, bar by bar, in Bb major. The roman numeral says the chord's place in the key, so the same chart works in any key.
| Bar | Chord | Numeral | Notes |
|---|---|---|---|
| 1 | G7 | VI7 | G B D F |
| 2 | Cm | ii | C Eb G |
| 3 | F7 | V7 | F A C Eb |
| 4 | Bb | I | Bb D F |
What the sheet music shows
The grand staff: the right hand on the treble staff, the left hand on the bass staff, with the chord names above and a finger number on each note (1 is the thumb). It is the accompaniment: lazy footsteps (root bass · 1 · 3 · 4) in the left hand, with the right hand free for the melody, over the G7 – Cm – F7 – Bb chords.
Press play and a cursor follows the music. Above it, Colours paints each note in its key’s colour and Note names writes its letter on its head.
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Questions about I Don’t Know Why
Does the sheet music for I Don’t Know Why have finger numbers?
Yes: every note of both hands has its finger number, 1 being the thumb. To read the notes alone, turn Fingers off above the music.
What chords are in I Don’t Know Why?
The loop is G7 – Cm – F7 – Bb (VI7 – ii – V7 – I) in Bb major, and the song ends on Eb – F – Bb.
What key is I Don’t Know Why in?
Bb major, at about 90 beats a minute in 4/4.
What does the left hand play in I Don’t Know Why?
Lazy footsteps: root bass · 1 · 3 · 4, an easy pattern. It follows the chords, so the same shape works for every bar.
Is I Don’t Know Why easy to play on piano?
Yes. Both hands play easy patterns over 4 chords. Learn the chords first, then add one hand at a time.
Made from one arrangement of this song: the left and right hands are the patterns these scores repeat most.