piano chord
F7sus4
F1B♭4C5E♭♭7
A dominant seventh with the fourth standing in for the third.
What is true of it
F7sus4 is F, B♭, C and E♭ — 1, 4, 5 and b7 counted from F.
On an instrument that cannot reach all 4, the 5 goes first, in that order.
F in other shapes
C7sus4C♯7sus4D♭7sus4D7sus4D♯7sus4E♭7sus4E7sus4F♯7sus4all 374