3 lights, light speed, no sound, 90 degree turn

Date was sometime in the early 70s.  The "Guess Who" band was playing at Milton Frank stadium in Huntsville,AL. I was about 2 miles from stadium, standing outside listening to the music.  An object appeared coming toward me from the west at a level of about 3 telephone poles. It stopped directly over my head. The form was muted from city lights.  It flashed in sequence 3 different colored lights (can't remember colors) forming a triangle. It then proceeded 90 degrees from where it had came at light speed. It never made a sound! I have tried to pinpoint the date, one would think it easy to find out when the concert took place.  If you are interested and can find out when it was, please let me know.  I told people that after stopping and flashing the lights on me, that they found no intelligent life and proceeded on!
Witness indicates that date of sighting is approximate.  PD