Where each triad comprises a root, 3rd and 5th interval, 7th chords simply add, you guessed it, a 7th! The magic of each mode lies in which root note you begin on. A Lydian mode (arpeggios ...
or A Lydian modes over this chord. Why not give each of these a try? If we reverse the order of chord and bass notes from Examples 1 and 2, we get B/A – a B major triad with an A at the bottom.