G-runs make the Bluegrass world go 'round. It is for this reason that 3...Count 'em... 3 G-runs have been provided for your Bluegrass enjoyment. G-runs are not just played at the end of a vocal phrase. They can be used to start a solo or even be used in the middle of a solo. It's hard to overuse the G-run, but it is possible. Use it until you start getting dirty looks...No...Use it until someone(who's opinion actually means something to you) tells you to stop :D