Bb Minor 7th

Bbm7 is a solid intermediate shape once open chords feel steady. The first shape is the easiest voicing: 4 fretted strings and 0 open strings. Put your index finger on the 1st fret of the G string. Put your index finger on the 1st fret of the C string. Put your index finger on the 1st fret of the E string. Put your index finger on the 1st fret of the A string. Strum all four strings and check each one rings cleanly.

Bbm7 is Bb, C#, F, G#. Those notes make a minor 7th chord. Play them in any order and you still get Bbm7.

Mellow and smooth: a minor chord rounded off with a laid-back, jazzy seventh. Chord quality is the interval pattern above the root. That pattern is what you hear as minor 7th.