Brian’s Bedroom

Hey Homerj742,

As far as I know, there is no way to change the tempo of a Hydrogen song automatically whilst it is playing. This leaves you little option but to use Ardour.

What you can do is to first record the slow part into Ardour, and then stop the recording. Then change the tempo in H2 and record that part into Ardour, either on the same track, or a whole separate track. You can then edit, splice and all that other good stuff to get the two tracks aligned. This can all be done within Ardour.

I hope that helps. Later,
Brian

This guys has achieved tempo changes:

http://www.linuxmusicians.com/viewtopic.php?f=19&t=2290

Tempo changes in hydrogen and ardour: Klick and tempomaps.

Postby Pablo on Mon Nov 02, 2009 9:11 pm
What we show:

- Use of tempomaps to reflect song structures, in a simple text file that klick and musicians can easily read.

- Tempo (including ramps) and time signature changes in a hydrogen song.

- Sincronization of hydrogen and ardour in non-fixed tempo (including ramps) and non-fixed time signature songs.

What we take for granted: Jack works stable

The software we need: klick, klick2ardour

http://das.nasophon.de/

Please, read the klick manual. (BTW, gtklick is a wonderful metronome with an intuitive GUI)

We will use klick as the jack master transport (-T option). We don’t want volume and pattern changes in the tempo maps for this. The Example Tempo Map in the klick manual, with not needed stuff removed:

###########################################################
intro: 8 120 # play 8 measures at 120 bpm (4/4)
verse1: 12 120 # 12 measures at 120 bpm
4 120-140 # gradually increase tempo to 140 bpm
chorus1: 16 140
bridge: 8 3/4 140 # change to 3/4 time
8 3/4 140
verse2: 12 120 # back to 4/4 (implied)
chorus2: 16 140 # jump to 140 bpm
outro: 6 140
2 140-80 # ritardando over the last 2 bars
#Number of bars: 40 4/4 + 16 3/4 + 36 4/4 = 92 bars
#############################################################

Now we have defined the structure of the song, we can have a hydrogen song with 92 squares… too much?

If the “one bar, one pattern” approach for writing drums seems awkward, we can also define “double” bars in the tempomap. So, one 8/4 counts for two 4/4 bars, one 6/4 for two 3/4 bars and so on. Following with the same example, now we will have:

###################################
intro: 4 8/4 120
verse1: 6 8/4 120
2 8/4 120-140
chorus1: 8 8/4 140
bridge: 4 6/4 140
4 6/4 140
verse2: 6 8/4 120
chorus2: 8 8/4 140
outro: 3 8/4 140
1 8/4 140-80
#Number of bars: 20 8/4 + 8 6/4 + 18 8/4 = 46 “double” bars
######################################################

Let’s copy the above to a text file that we can name… tempomap.

In hydrogen, each square in the song editor will correspond to patterns of the following sizes:

From square 1st to 20th: size 16
From 21st to 28th: size 12
From 29th to 46th: size 16

For starters, let’s try with just two simple patterns. The song editor looks like this (o means void):

pattern1(s16): xxxxxxxxxxxxxxxxxxxxooooooooxxxxxxxxxxxxxxxxxx
pattern2(s12): ooooooooooooooooooooxxxxxxxxoooooooooooooooooo

In hydrogen, select jack transport (no jack master) and song mode. Do in the terminal:

Code: Select all
klick -T -f /path/to/tempomap

Then press play in whatever jack transport (hydrogen, qjackctl)… Yes, Hydrogen with tempo changes.

You can also export a tempomap to ardour with ‘klick2ardour’ and then use ardour as the jack master to drive a “non-fixed-tempo, non-fixed-time-signature” hydrogen, without further need of klick. In adition, intro, verse1, etc, markers will be created in the right locations. :)

Thanks a lot to Dominic and Hydrogen and Ardour developers for making this posible. You rock!