Tricky chords, not even sure if possible

I’ve been playing guitar a lot longer than I’ve been studying music theory and in an attempt to transcribe one of my own compositions, which has lots of move-your-fingers-about-until-it-sounds-nice type chords, I’ve hit a brick wall. Any help would be much appreciated.

I’ll just give the notes of the chords, low-to-high.

Bb F G D
Bb E G C
Eb G Bb G
Eb G A F

In my brain that looks like Bb6, something weird, Eb, something weird. I’m not even sure what key this is in. Trying to make those chords in Bb or Eb seems impossible. Later chords include F, Gm, C, and some other oddities :smile:

Thanks in advance.

The two weird chords are dominant 7th chords but inverted so the 7th degree is the bass note. First one is C7/Bb, next one is basically F7/Eb except it has a G in there so more like F9/Eb. You’ve stumbled across a really nice type of chord - they’re especially useful as passing chords, for example the last one is a great lead-in to Bb/D