Chord "Deux" Jour Challenge: G7 and Bm7b5

I challenge you to learn two chords every day, until the last day of the season (December 20). If you've missed a day, please refer to this list. You have your choice between the guitar and the piano (keyboard), or both. If you're a beginner, I'll show you relatively simple ways to play each chord. If you're more advanced, you'll have the entire fretboard and/or keyboard to explore.

Simple guitar chord shapes are marked with a number representing the recommended fingers to use for fretting a chord:

1 index finger
2 middle finger
3 ring finger
4 little finger
o play open string
x do not play open string
( bar one finger over more than one string
T that rare occasion that I recommend you use your thumb to fret a note

Today's first chord is G (major minor) 7th; the combination of a major chord and a minor 7th note make it a dominant 7th chord. Just keep that in the back of your mind as you actually learn (or expand upon) the G7 chord:

Guitarists, you might think of the G7's shape like a C chord, but expanded to the edges of the guitar neck -- your index finger (1) goes to the high E string; your middle finger (2) goes to the A string; and your ring finger (3) goes to the low E string.

Keyboardists, G-B-D-F spell out G7. You might notice that there is a Bdim lurking inside of G7. On many occasions, G7 might be a more pleasant (less unsettling) substitute for the B diminished chord.

Here's B minor (minor) 7th flattened 5th, or Bm7b5:

Guitarists, take the Bdim chord, and lift your little finger. Your index finger should be fretting three strings -- A, D, and G strings, but only two of them will count.

Keyboardists, B-D-F-A combine to become Bm7b5. Like G7, I consider this a 'child' of Bdim, of sorts. Anyhow, the extra note makes Bm7b5 more palatable than Bdim, but they both tend to be chords played in passing, between two other chords. Or so they say ...

Two more tomorrow! Cheers!