Automatic Beat Detection
Song Surgeon Version 5 contains automatic beat detection. When you open a song, Song Surgeon automatically calculates the BPM of that song. This BPM is used to calibrate the tempo and metronome for that song as it opens in the program. To be specific, if the BPM is calculated at 120, that Tempo value will appear in the Time Display area above the main playback controls. This value of 120 BPM value will increase or decrease within this display as, as the tempo is adjusted up or down by the user.
Continuing the above example, the metronome setting is also set to 120 for this song, as the song opens. Thereafter this BPM value will can be adjusted by the user from this starting point.
Before implementing this feature we compared and tested several different technologies. Here is a summary of what we found:
The BPM readings from Song Surgeon Ver 5 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 Song 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 it is irrelevant which value is used as the default value from which to increase or decrease the tempo, because either one can be used as a starting reference point from which change can be measured.
Below is a comparison table of BPM data comparing Song 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|