Automatic Beat Detection
Audio Surgeon contains contains a module that calculates or determines the tempo (BPM) of an
audio file or song. Tempo can be an important parameter for musicians and DJ's. For example, DJ's like to use BPM for creating
playlists of songs with similar tempos.
Audio Surgeon uses tempo as a unique parameter for determining duplicates. In addition, AS has the ability to change the tempo of a file or group of files. When it does this it uses the calculated BPM or Tempo as the starting point for such changes.
Before implementing this feature we compared and tested several different technologies. Here is a summary of what we found:
The BPM readings from Audio Surgeon were comparable to, and as accurate as, the best available technology.
The BPM technologies we tested worked well with Rock, Country and Pop music. They were less reliable with Jazz. They were the least accurate with Choral and Orchestral music where there often is no defined pulse.
There are times when the bpm reading may be off by 50%. This is due to the fact that the programs are not given the “metrical level”. In other words, they are not told, and have no way of knowing, the time signature for each song, e.g. does the quarter note get 1 count, or the eight or the half. By default these programs typically will display the faster of the BPM rates.
Even when the numerical BPM value being displayed for a particular song is not correct, the program is detecting a musically correct pulse, i.e. in time with the music. For example Audio Surgeon calculates the BPM of the song “Hotel California” to be 148. The true value from the sheet music is 74, or ½ that value. In the bigger picture both values accurately depict the pulse of the song.
Below is a comparison table of BPM data comparing Audio Surgeon to its competitors across a range of different musical genres.
|Baby, Now That I've Found You||118||118||118||117||118|
|The Heart of the Matter||176||176||176||89||87|
|Louder Than Ever||139||NA||185||140||70|
|Just the Girl||111||111||111||112||112|
|Here We Go Again||142||142||142||144||143|
|Vivaldi four Seasons - Winter||148||145||144||148||141|
|Arrival of the Queen||108.01||107||163||108||80|
|Mozart Piano Concerto No. 21||166||114||115||115||55|
|Pachelbel Canon id D||130||132.44||117||133||60|
|One Finger Snap||238||155||NC||92||128|
|Take the A Train||79||158||170||161||80|
|The Girl From Ipanema||123.74||125||123||126||61|
|Sing, Sing, Sing||108.54||108||NC||110||110|
|O Nata Lux (Lux Aeterna)||168||NC||NC||144||72|
|Like Snow (Midwinter Songs)||152||NC||NC||144||72|
|Lament for Pasiphae (Midwinter Songs)||138||NC||NC||136||66|
|Intercession in Late October||152||NC||NC||117||100|
To learn more about Audio Surgeon go to our main page. There you will find an introductory video as well as an overview of the major features found in Audio Surgeon.