Bars and Beats Based Cues

[micpool]

I have finally discovered a reliable quick way to use bars and beats to trigger QLab cues.

In the attached screen recording, all the video and text cues have notes on MIDI Triggers with the Bar Number entered as the note number and the velocity as the beat in that bar.

For convenience, the  note and velocities are shown in the cue numbers e.g. 6.7 is Bar 6 Beat 7

The tempo map of the MIDI file cue is shown at the bottom of the recording. The tempo swings wildly between 74 and 120 bpm, and there are bars  in 4/4, 6/8, ¾, 7/16, and 9/8

As you can see, every cue happens precisely on its allotted beat.

The thing that makes this work is the MIDI file, which is generated automatically in real-time from a standard DAW metronome click (one note on the downbeat, a second note for all the other beats in the bar) using a little app that receives the metronome from the DAW. Counters increment the note number once per bar, and the velocity increments from 1 to the number of beats in the bar for each beat until the next bar starts. 

So, every beat sends a unique MIDI note number and velocity, which is its bar number and beat number in that bar. The Bar and beat numbers can be quickly read off a score and entered as the MIDI triggers for the cue you want to happen on that beat.

And yes, if you change the playback rate of the audio and MIDI files, e.g. to 0.9, the cues still happen precisely on the correct beats.

Mic

[Drew]

That is super cool.  I've been using slices in a very rudimentary way with twisted wave just so I can have a time reference for LDs when they want to hit something on the beat. It is very time consuming though.  Marker up each two track with bars and beats and have that as a silent reference at the top of the group containing the stems.  Time consuming work before going into the theatre, but time saving in the theatre with our rhythmically challenged lighting friends and where the bulk of the production expenses occur. 

[Drew]

Hey Mic, I think I am misunderstanding something here.  I'm just trying to test this out.  Do you need to run your DAW live with QLab and another piece of software to translate the midi to the tempo map midi?  Or is QLab referencing the midi file tempo map? 

I have exported a tempo map from my DAW as a midi file, i have some text cues with a midi trigger for each cue corresponding to bar and beat.  My tempo map does not look like yours though.  It doesn't appear to have the beat markers that yours have underneath the tempo map lane.  Maybe I am exporting my my midi file somewhat incorrectly.  Ise Digital Performer.  I shall try another DAW and see if that helps.

Thanks
Drew

[micpool]

The thing you are misunderstanding is how the MIDI file is made.  You need another piece of software to  take the 2 note click generated by a DAW e.g note 60 for first beat in a bar, note 61 for all the other beats in a bar, and turn it into a file where every beat has a unique MIDI note/ velocity combination.  So in effect what you are making is a very low resolution timecode, in so far that every frame is unique,, but one where every frame is precisely aligned to the tempo and beat of a piece of music. Once that is made, you put that in QLab in a timeline group together with the audio, or multiple audio cues if you are using stems.

The additional software can be made in anything that can process MIDI quickly and intelligently e.g MAX, Vuo.a proper programming language with a MIDi code library etc.

Every time the click track MIDI Note for Beat 1 is received a note counter advances the note number and resets the velocity number to 1.

This note is sent back to the DAW on a different MIDI bus to be recorded in real time as the click plays e.g note 48 velocity 1

Every subsequent beat in the bar increments a velocity counter  by 1 and sends that note back to to the DAW for recording e.g note 48 velocity 2, until the next downbeat is received.

Obviously,  there is a huge limitation with this proof of concept version  as song length is  limited to 127 bars if you want the simplicity of being able to program  a cue to trigger on a bar/ beat by just entering those numbers into the note number and velocity of a MIDI trigger for a cue. 

Mic

[Drew]

Thanks for that Mic.  I shall have a go.  Looks really great and would be very useful.