Introducing The Step Sequencer

I wanted to use the Logic Pro X Step Sequencer for this assignment, partly because I wanted to learn how to use it, and partly because step sequencing was one of the requirements. So today I converted my MIDI drum rhythm cells to Step Sequence cells using largely the same pattern, with two changes:

• Shifting the start of the pattern to beat one
• Changing the Play From Start, Start position to compensate for the vocals starting before beat one of the bar
• Adding a Hi-Hat ride, skipping some beats to syncopate with the vocal rhythm

Here’s the now-defunct MIDI version of the rhythm pattern:

Logic Pro can convert Step Sequencer patterns to MIDI patterns, but not the reverse since the MIDI pattern is more general, so I recreated the pattern manually.

Here’s what the rhythm pattern looks like in the Step Sequencer:

Changing the Play From Start, Start position makes the rhythm look more normal in the Step Sequencer, since beat 1 is now at the start of the sequence. This means the same pattern can be used for all verses tweaking the Play Start position as follows:

Verse	# 32nd Notes Vocal Early	Play Start
1	5	1 4 2 121
2	2	1 4 4 1
3	6	1 4 2 1
4	5	1 4 2 121
5	5	1 4 2 121

This still doesn’t solve the inherent problem of the rhythm glitching when moving between scenes from verses with different degrees of vocal anticipation, but I’ll worry about that later.

In doing this I encountered three bugs in Logic Pro which are probably related:

• The cells get out of sync when pressing Start/Stop/Space to start and stop play because the drum cell doesn’t start exactly where it stopped. My guess is this is because the Start position is fractional (ie: 1 2 1 121)
• Fractional start positions with more than two numbers in them don’t display in the Cell inspector
• The fractional part of start positions gets lost if you edit it in the Cell inspector

I figure if you aren’t hitting bugs in Apple software, you aren’t being creative enough.

More Vocal Processing

I also added more processing to the Vocals to further reduce extraction artefacts and breathe life back into them by creating a wall of sound. Phil Spector would be proud; if he still cares anything about music production after all these years in jail.

I started with these plugins to reduce artefacts:

• Compression to smooth out variations in the extracted vocal level, set to Dual Mono so each channel is processed separately to reduce extraction artefacts

Vocal Compressor

• Gain set to Mono, to convert the stereo vocals imported from RX 8 to mono, further reducing artefacts in the stereo spread.

The vocals would have been originally recorded on a single microphone, so any stereo difference is an artefact either of the original production or extraction process.

Then I added these plugins to create a wide stereo image with more spaciousness:

• Stereo Spread plugin at 74%

• Stereo Delay of +20 ms on the Right channel

• Gain balance +35% to the Right to compensate for temporal masking and maintain psychoacoustic balance

• Space Designer reverb on Empty Church, which seems fitting given the references to God in the lyrics, with Length 641 ms, 0 dB Dry and -19 dB Wet

I also threw on a third Gain plugin at the end of the chain set to Mono, to check that my Stereo Spread and Stereo Delay plugins aren’t causing any phase cancellation issues for any listeners who may end up hearing this in mono. It seems fine, so I switched the plugin off. I double checked this with the Correlation Meter as a further confirmation that stereo spreading isn’t introducing phase cancellation issues.

This means the Vocal track has three Gain plugins, each for a different purpose:

1. Convert to Mono
2. Compensate for temporal masking from the Stereo Delay
3. Test for phase cancellation (Disabled)

Each plugin has a different function at a different position in the audio chain, so they can’t be combined to reduce CPU usage; even though this isn’t a big deal since the Gain plugin uses minimal CPU anyway.

Here’s how the project looks now:

Here’s a sample of a few lines from my favourite verse:

Tomorrow I get cracking with Granular Synthesis in Alchemy, and what I have in mind is quite shocking…