Yah but even very rudimentary beat detection will suffice for visuals, because if it interprets a "false beat" it doesn't really throw off visualizations much. But one false beat in actually calculating and displaying a BPM value is much different. I only found one software implementation of BPM calculation (well only one automatic one that didn't involve clicking the space bar to count beats) which had any accuracy at all in displaying BPM correctly, and it usually took 30 seconds for it to figure it out.

Of course no BPM algorithm is going to get 100% of songs due to tempo changes. hard-to-detect beats, etc... But the ones I've seen have been so bad that they're basically worthless.

-Tony
MkII #554