Mmm, juicy topic. I am into range prediction, so the previous day's range and the next day's volume are the two main factors used to predict the next day's reversal points, combined with S&R levels such as previous high, low, and pivot point. Once I added pro-rata volume (PRV) to the mix, it was amazing how many times the distribution of the daily range over time tracked the PRV. The lower the volume, the better the prediction of that day's range using the PRV.
Above-average PRV is an entirely different story. There, you have to switch to the principle of alternation (NR WR NR repeat). Your range prediction switches to a breakout/consolidation pattern cycle, and you will observe high-volume NR days in preparation for a high-volume WR day.
To answer the question, does volume lead price? Sometimes, but price can lead volume, too. The market is a funky beast.