If I Should Lose You by Ralph Rainger

Overview

Key: B♭ major · Chords used: 16 · Sections: 4

Form: A Section → B Section → A Section → C Section

Where these chords come from: a chord chart of this song written by a musician and shared on the iReal Pro forums, archived in the iReal Pro forum charts archived in ChoCo (de Berardinis et al., 2023). It's one musician's reading of the song, not a transcription checked against the recording. This page shows that chart as-is: the analysis below is generated directly from it by code, not written by AI. Consecutive repeats of a chord are shown once, and the piano voicings are our playable arrangement of each chord symbol, not a note-for-note transcription.

Section by section

A Section 1

• Gm7 – Am7♭5 – D7♯9 – Gm7 – F♯7
  vi7 – viiø7 – III7#9 – vi7 – #V7
• Fm7 – B♭7 – E♭maj7 (×2)
  v7 – I7 – IVmaj7

B Section

• Cm7 – F7 – B♭maj7 – Am7♭5 – D7 – Gm7 – C7 – Cm7 – Cm7/B♭ – Am7♭5 – D7
  ii7 – V7 – Imaj7 – viiø7 – III7 – vi7 – II7 – ii7 – ii⁴₂ – viiø7 – III7

A Section 2

Same chords as A Section 1.

C Section

• Cm7 – F7 – B♭maj7 – D7♭9 – G7 – Cm7 – F7 – B♭6 – Am7♭5 – D7
  ii7 – V7 – Imaj7 – III7b9 – VI7 – ii7 – V7 – I6 – viiø7 – III7

Chord vocabulary

Chord	Roman numeral	Role	Heard in
Gm7	vi7	In the key	A Section, B Section
Am7♭5	viiø7	In the key	A Section, B Section, C Section
D7♯9	III7#9	Secondary dominant (V/vi)	A Section
F♯7	#V7	Outside the key (chromatic)	A Section
Fm7	v7	Borrowed from B♭ minor	A Section
B♭7	I7	Secondary dominant (V/IV)	A Section
E♭maj7	IVmaj7	In the key	A Section
Cm7	ii7	In the key	B Section, C Section
F7	V7	In the key	B Section, C Section
B♭maj7	Imaj7	Home chord (tonic)	B Section, C Section
D7	III7	Secondary dominant (V/vi)	B Section, C Section
C7	II7	Outside the key (chromatic)	B Section
Cm7/B♭	ii⁴₂	In the key	B Section
D7♭9	III7b9	Outside the key (chromatic)	C Section
G7	VI7	Secondary dominant (V/ii)	C Section
B♭6	I6	Home chord (tonic)	C Section

Harmonic highlights

• Fm7 (v7) is borrowed from the parallel key, B♭ minor.
• D7♯9 acts as V/vi: it resolves to Gm7.
• B♭7 acts as V/IV: it resolves to E♭maj7.
• D7 acts as V/vi: it resolves to Gm7.
• G7 acts as V/ii: it resolves to Cm7.

Sources & accuracy

• Chords: the iReal Pro forum charts archived in ChoCo (de Berardinis et al., 2023). Community chord chart “If I Should Lose You” (credited “Rainger Ralph”, style Medium Swing) from the forum file linked here, CC BY 4.0 via ChoCo. Performer/songwriter confirmed from Wikidata.
• Section names: from the chart's own markings: section names written on the chart (Intro, Verse, Chorus…) are kept, and rehearsal letters are shown as “A Section”, “B Section” and so on (the B of an AABA song is called the Bridge).
• Cross-check: the iReal Pro forum charts archived in ChoCo (de Berardinis et al., 2023). Community chord chart “If I Should Lose You” (credited “Rainger Ralph”, style Medium Swing) from the forum file linked here, CC BY 4.0 via ChoCo. Performer/songwriter confirmed from Wikidata. A separately posted chart of the same song; its chords match this page's closely when both are read in the same key (similarity 74%).
• Chord charts are often written in a key that suits a particular singer or band, so this may not be the key of the original recording.
• About the song: Wikipedia.
• Verified: two community charts of this song, posted in different forum threads, agree on its harmony. They're still charts, not transcriptions checked against the recording.
• Rhythm and chord durations aren't shown; each step is one chord change.