A #5th is often referred to as augmented, so if you see A7(aug 5) on a chord chart, this is it! This would be a D9 chord, but if we look at it from low to high, we have: root (D) - major 3rd (F# ...
However, another way of looking at it could be as an augmented 4th (C to F# ... Now we’re ready for the I chord. The I of our II-V-I (D) sounds a bit plain after all that, so I’m opting ...
In the jazz styles of Gershwin and Kern, the dominant seventh was often substituted with an augmented chord.This gave the tonic-dominant a new and modern feel. This can be heard in Can’t Help ...