I'd suggest playing darude - sandstorm on loop, fairly loudly but with a (cone) directional speaker pointing straight upwards, spiraling in towards mission & 20th st starting ~6 blocks out in each direction. Record the time when you reach each intersection, and you'll know exactly which street segment you were on when your song got shazam'd, without having to actually ride on every segment (save roughly 50% travel time compared to doing the full grid).