Selkie Hum help

How I use it

I sing into a microphone on a MOTU UltraLite-mk5, which sits on a USB hub into a 12-inch iPad Pro. I hear myself through in-ears from the interface. Loopy Pro runs on the iPad and Hum sits on a vocal track in it, after a noise gate, sending MIDI to a synth on another track. Scalar 3 and SWAM Violin, mostly.

When I sit down I set levels and the gate for the mic, though the noise gate ahead of Hum does most of that work. Then per instrument: the octave shift that puts a violin or a pad where I want it, and velocity. For simple melodies I leave velocity at Fixed so every note comes out the same. For pads and atmospheric sounds I turn it up so I can swell a note in with my voice, unless the instrument already does that itself. I save a Loopy preset per instrument so I can get to each one quickly on stage.

For each song I pick the scale the song is in. Then I hum.

What goes wrong: if my voice isn’t warmed up, notes flicker. More smoothing sorts that out.

On its own

I don’t use the app without Loopy. If I did, I’d open Hum, then open a synth app and pick Selkie Hum as its MIDI input. Hum keeps listening in the background while the synth app is in front. I’ve done that with Scalar 3. I’ve also plugged the iPad into a Mac over USB, enabled it in Audio MIDI Setup, and had the notes arrive in a MIDI monitor there. The button at the top pairs a Bluetooth MIDI keyboard or synth.

The app makes no sound of its own. Anything it played would come straight back in through the microphone.

The panels

Stage

Your voice on the left, the note it became on the right.

The meter is how loud you are. The line across it is the gate: below that line nothing counts as a note. Drag the line to set it. With the gate too low, breath and room noise become notes. Too high, and quiet singing is ignored.

The scope behind the note is your voice’s waveform, a few cycles of it.

The note on the right is what was sent, after the scale and the octave shift. Octave shift moves every note up or down by whole octaves before it leaves, so a voice can play a bass or a piccolo.

Autotune to scale

Off means any note goes. Pick a key and every note you sing snaps to it.

Choose a scale from the row, then a root on the keys. A note off the scale goes to the nearest note in it. Off is every semitone, which means a slightly flat note comes out as the note below.

Note

How patient the plugin is before changing note, and how loud the notes come out.

Smoothing is how sure the plugin has to be before it changes note. Turn it up and it waits longer, so a wobble in your voice doesn’t become a new note. Turn it down and it follows you faster but may flicker.

Velocity is how loud each note starts. At Fixed every note is full volume, however you sing. Turn it up from there and quiet singing gives quiet notes. Turn it further and it takes real force to get a loud one. Whether that changes anything depends on the synth.

MIDI

Where the notes go.

Output on or off. Off ends the current note and sends nothing until it’s on again. Aftertouch sends how loud you are while a note is held, as channel pressure, so a synth that listens to it can swell. MIDI channel is the channel the notes leave on.

Panic at the top ends the current note and tells the synth to stop everything on that channel. Use it if a note sticks.

Audio

How much of your own voice carries on past the plugin to whatever’s next.

Voice through at full lets your voice continue down the track. At zero the track goes quiet and only the MIDI leaves. In the app on its own it does nothing, since the app makes no sound.

What it doesn’t do

• One note at a time. Sing a chord and it picks one.
• No pitch bend. Sliding between notes is a step, not a glide.
• No sound of its own. It needs a synth on the other end.
• iPad and iPhone only. There’s no Mac version yet.