I am playing BY A MEADOW BROOK from Edward MacDowell and here I found an example of half diminished chord.
We often hear about diminished seventh chord (Dim 7th). The note structure is very easy to remember - the interval between each notes are three semitones apart.
Example: C Eb Gb A makes a Cdim7th chord. And what's interesting about Dim7th chord is they are enharmonic chord for each of the chord member. So: Cdim7th is equal to (have the same chord member as) Eb, Gb and A diminished 7th chord. Which is why we only have three diminished 7th chord (so to speak :)
Right now let's move on to Dim7th twin brother. Here is the half diminished chord or halfdim for short. To make it easy to remember: halfdim chord has an almost similar interval with Dim7th chord except for the fourth note. The fourth note interval must be four semitones apart instead of three.
Example: C Eb Gb Bb makes a C halfdim chord.
Isn't that cool??!!! 😂😂😁
Happy practicing!