Lots of great questions came up in the comments, so lets address them here.
Why do you need to beatgrid?
- In Traktor Pro, Locking SYNC, or locking on tracks grid to another will not work without a grid.
- Beatgrids allow for quantized beatjumps, loops and cue jumps even in breakdowns
- to get the precise BPM of a track
- for older songs and rock tunes, set a grid on a clean rhythmic part (like a drum intro) and loop that section while mixing.
- for electronic songs that float, try placing several beatmarkers
- for material that must be in time over long sections, use albeton live to warp the track and then export an adjusted version for dj play.