document new BPM search options

source/chapters/library.rst

@@ -426,25 +426,35 @@ Mixxx supports the following filters:
       title:= "Track 1"
       artist:="DJ Flop"
 
-* **Numeric filtering**: bitrate, bpm, played, rating, track, year
+* **Numeric filtering**: bpm, bitrate, played, rating, track, year
 
   Examples
     ::
 
-      bpm:140
-      bpm: >140
       year: <2010
-      bpm: >=140
+      rating:<4
       rating: <=4
-      bpm: 140-150
+      rating:3-5
       played: >10
 
   .. note::
      You can put a space after the colon but currently there must be no space
      between the operator and the number.
 
+  * By default, `bpm:` finds tracks with the exact BPM but also half and double
+    values. If the half or double values are not integers, ranges are used. The
+    following example lists tracks with 125.2, [250-251] or [52-53] BPM
 
-* **Special filtering**: key, duration, added, dateadded, datetime_added, date_added
+    ::
+
+      bpm:125.2
+
+  * Use `bpm:=` to find exact matches only, i.e. exclude half/double values.
+
+  * `bpm` also supports fuzzy searches, see Special Filtering below.
+
+
+* **Special filtering**: bpm, key, duration, added, dateadded, datetime_added, date_added
 
   * Supports fuzzy matching of key searches. The following example lists tracks
     with harmonically compatible keys to C# minor.
@@ -453,6 +463,16 @@ Mixxx supports the following filters:
 
        ~key:c#m
 
+  * Fuzzy BPM searches find tracks in the range of +/- N % of the current pitch
+    slider range. N can be set in :menuselection:`Preferences --> Library --> Track Search`.
+    With the default pitch slider range of 8% and the default BPM search range
+    of 75%, the following example lists tracks with BPM between 94 and 106.
+
+    ::
+
+       ~bpm:100
+
+
     The following example lists all tracks by “Danger” over 3 minutes long that
     are rated 4 or 5.