PSA: Cloud Analysis is problematic; you may want to disable it as it causes variable tempo / incorrect BPM results

Hi there,

tl;dr: I would strongly encourage everyone to disable Cloud Analysis mode, because it seems to sometimes have cached bad analysis results from other Rekordbox customers. It's also possible that it's using cached results from customers who use a different Track Analysis mode than what I do (Dynamic instead of Normal, even though my settings are set to "Normal").

Edit: I've now confirmed that it does appear to be caused by Rekordbox fetching a Cloud Analysis using a different Track Analysis mode, by switching my analysis mode and re-analyzing one of the problematic tracks. That's really silly.

I've been using Rekordbox for something like 6 years now, and with my software doing its Track Analysis in "Normal" mode I've basically had no issues over the years. It does a good job recognizing the BPM of tracks and setting the beat grid, but over the last few months I've started to run into some songs (1/100?) that I import and analyze and the BPM appears to be variable throughout the whole track even though it's a modern four-on-the-floor EDM track. Makes it harder to set hot cue and memory points, if you prefer to use the Quantized mode.

I had seen this problem before when I accidentally put the software in "Dynamic" Track Analysis Mode, and then I fixed it by setting it to "Normal" and then re-analyzed the tracks. But as of recent no matter how much reanalyzing I do of the track the BPM changes constantly throughout the track, and it was driving me mad.

Today I started to try to figure this out again, and I saw a setting I had not noticed before: "Cloud Analysis". This feature causes Rekordbox to check Pioneer's servers for a cached Track Analysis result, uploaded by other customer's Rekordbox software. The sell of this feature is that if it works correctly, you will be able to analyze tracks much faster when importing them.

Unfortunately, it seems like maybe there are some cached analysis results that are just wrong, or were generated using a different Track Analysis mode than what I am using in Rekordbox. Because after I turned this setting off and re-analyzed some of the tracks, the variable BPM issue I was seeing with these tracks went away.

So I think this feature is fundamentally flawed, in that it:

1. Seems to be possible to fetch faulty Track Analysis results.
2. Fetches Track Analysis results that were generated using a Track Analysis Mode that differs from your Rekordbox settings.
3. Has no way for Rekordbox users to report an analysis as being faulty, or to have Rekordbox analyze single tracks without fetching Cloud Analysis results (except for turning it off completely).

For anyone who is running into the issue where the BPM of their tracks randomly change through the track itself, hopefully setting your Track Analysis Mode to "Normal" and disabling "Cloud Analysis" will fix it for you like it did me.