I am trying to work up a GJ version of cheese cake (Dexter Gordon) out of a fake book of dubious origin, and it has a chord represented by a D, greek phi (circle with a vertical line), 7. I can not figure it out. I have seen greek-delta (triangle) 7 represent a major 7th before but never a PHI. Any ideas? The melody has a G in it. I uploaded the chart.