Groovy Metronome uses a powerful script language to make metronome tracks. We'll explain the syntax of the script language by example.

Let's first point out a difference between the Groovy Metronome script language and conventional time signature notation. In general, a time signature specifies how many beats or pulses are contained in each measure or bar, and which note value (quarter note, eighth note, ...) is equivalent to a beat. Groovy Metronome is only interested in the first part of conventional time signature notation. It wants to know how many beats are contained in each measure. Whether these beats are quarter notes or eighth notes is irrelevant for Groovy Metronome, as the length of a beat is simply controlled by the rotational knob on the front page of the app that indicates the BPM or beats per minute.

Therefore a simple 4/4 time signature can be represented by the following script:

4

This script will provide 1 heavy beat and 3 light beats, repeated over and over. However, in modern music it is more conventional for the 4/4 time signature to have a heavy beat followed by a light beat followed by another heavy beat followed by a light beat. We can split up the previous script in two beat patterns:

2+2

The 2+2 script will give a heavy beat and light beat (caused by the first 2) and another heavy beat and light beat (caused by the second 2). The + sign in the middle is actually purely cosmetic. The script 2 2 will give the same result.

A 3/4 time signature can be represented by:

3

yielding one heavy beat followed by two light beats.

An odd meter time signature like 7/8 is more interesting. We can represent it by the following three different scripts, depending on where you want your heavy beats to be:

3 + 2 + 2

2 + 3 + 2

2 + 2 + 3

Again the + signs above are purely cosmetic.

The next example is based on the famous song "America" from the musical "West Side Story". This song employs a mixed meter where we have alternating bars of 6/8 and 3/4. The distinctive characteristic of this song is determined by how the heavy and light beats alternate. We can use the following script:

| 3 + 3 | 2 + 2 + 2 |

Here we have used | signs to distinguish between different bars. The first bar has a heavy beat followed by 2 light beats twice, while the second bar has a heavy beat followed by a light beat three times.

The Groovy Metronome script language also has functionality for repeating several bars. This is done by using the combinations ||: and :|| that should look familiar to musicians that need to read sheet music often. Let's take a look at the following script:

||: 2+2 :|| 3 |

This script has two (because of the repeat signs) 4/4 bars followed by one 3/4 bar. Suppose that we want three 4/4 bars followed by one 3/4 bar, then we can add *3 to :||, where *3 means "do this three times":

||: 2+2 :||*3 3 |

In this way you can repeat segments as much as you want, for instance:

||: 3 + 3 | 2 + 2 + 2 :||*8 ||: 3 + 3 :||

This script will alternate 6/8 and 3/4 eight times, followed by two times 6/8.

The last feature of the Groovy Metronome script language has to do with tempo changes. You can fix the tempo in your script. If, somewhere in your script, you add t=120, then the tempo changes to 120 beats per minute. For instance:

| 2 + 2 | t=120 2 + 2 |

This script will play one 4/4 bar in the tempo as indicated by the rotational knob on the front page of the app, and will continue with another 4/4 bar at 120 beats per minute. This is then repeated over and over, so you get 4/4 bars alternating between the tempo from the rotational knob and 120 beats per minute.

It is also possible to change the tempo relative to the current tempo. This is done by the notations t*=1.5 (make the tempo 1.5 as fast, so a bpm of 100 becomes 150), t/=2 (divide the tempo by 2, so a bpm of 200 becomes 100), t+= 5 (add 5 bpm to the current bpm), or t-=5 (subtract 5 bpm from the current bpm). The America song from West Side Story can thus also be represented as:

| 3 + 3 | t/=2 3 |

Indeed, the first bar is our 6/8 bar as in the previous America script. The second bar now contains 3 beats only, but the tempo is halved.

The relative tempo changes allow also for some fun. The following script will play eight 4/4 bars and will then up the tempo by 5 bpm:

||: ||: 2 + 2 :||*8 t+=5 :||*20

The increasing of the tempo is performed 20 times, so the final loop will run 100 bpm faster than the initial tempo. After this last loop the script reruns at the original tempo and starts to increase its tempo gradually again.

Finally we mention that it is possible to add comments or descriptions to your script. Simply place your comments between round brackets, for instance:

| 2 + 2 (This is a standard 4/4 bar) |

• standard 2/4 bar

2

• standard 3/4 bar

3

• standard 4/4 bar

2+2

• standard 6/8 bar

3+3

• odd meter 7/8 bar, version 1

3+2+2

• odd meter 7/8 bar, version 2

2+3+2

• odd meter 7/8 bar, version 3

2+2+3

• one bar of 6/8, followed by one bar of 3/4 (cfr. America from West Side Story)

| 3+3 | 2+2+2 |

• two bars of 4/4, followed by one bar of 3/4

||: 2+2 :|| 3

• seven bars of 4/4, followed by one bar of 3/4

||: 2+2 :||*7 3

• odd meter 9/8 bar with standard subdivision

3 + 3 + 3

• odd meter 9/8 bar, organized as a standard 4/4 bar with one extra eigtht (cfr. Voices by Dream Theater)

2+2+2+2+1

• standard 4/4 bar with increasing tempo (adding 15 bpm per new bar)

||: 2+2 t+=15 :||*10

(intro)

||:4+3+3:||*3 3+3+3|

||:

(guitar)

||: ||:4+3+3:||*3 3+3+3 :||

| 4+3+3 | 2+2+3+3 | 4+3+3 | 3+3 | 3+3 | 2+2 |

| 4+3+3 | 2+2+3+3 | 4+3+3 | 3+3 | 3+3 | 2+2 |

:||

||: 3+3+3+2 | 3+3+2+2 :||

||: 3+3+3+2 | 3+3+2+2 :||

||: 3+3+3+2 | 3+3+2+2 :||

3+3+2 | 4+4 |