Front Porch

Rhythm guitar played on an electric piano. A Chord Sequencer strums G, D/F♯, Em7 and Cadd9 the way a guitarist's hand moves: down on the beat and up on the offbeat, rolling each chord across its strings, digging into the first strings it hits and only brushing the last. Under the chords, the bass walks down G, F♯, E, C. Below them, on the porch boards, a heel keeps time on 1 and 3, and a shaker plays sixteenths that lean on the upstrokes.

Load it: choose 📚 Examples → Front Porch in the toolbar and press ▶ Play. It needs no keyboard. The patch file is patches/front-porch.json.

Or play it here: press ▶ Play in the corner. The full app is a click away under Open in Soba. The hand, the instrument and the room along the top, and the porch under the hand. Everything that makes it sound like strumming happens in the Chord Sequencer: the Electric Piano is the Library's, unchanged. The one Clock plays the hand and the porch, and a Mixer brings them into the one room.

What it teaches

• Strum. Each note of a chord starts a little after the one before it, as a pick crosses the strings one at a time.
• Strum dir Alt. The hand goes down on one clock and up on the next. It keeps moving through held chords, so downstrokes always land on the beat.
• Taper. The strings struck last are softer, so an upstroke brushes the bass instead of hitting it.
• A rhythm from ties and velocities. A tie leaves out a stroke, and a lower velocity makes an upstroke lighter. Together they make a strumming pattern out of a plain eighth-note clock.
• A guitar's voicing. Spread voicing with a bass voice puts five notes over two octaves, about where a guitar's six strings put them.
• Percussion that follows the hand. A Trigger Sequencer counts the same eighths as the strum, so each of its pads sits under a stroke. A ×2 ratchet turns an eighth-note lane into a shaker's sixteenths.

Modules

How it's built

The hand

[Clock Gate]  ──> [Chord Sequencer Clock]
[Clock Reset] ──> [Chord Sequencer Reset]

The Clock ticks in eighth notes, eight to a bar. Each step is one movement of a guitarist's strumming hand, and the progression is four chords of half a bar each, two bars in all. Every half bar has the same shape:

Count it "1 (and) 2 and": a downstroke that rings, the hand coming up without touching the strings, then down and up. Step 1 is tied into step 2, which holds the chord instead of playing it again. With Strum dir on Alt, the hand still turns on that clock, so step 3 is a downstroke and step 4 an upstroke. Upstrokes play at a lower velocity than downstrokes, as a guitarist's do.

Cadd9, the last chord, plays all four strokes, down up down up, at velocities 104, 64, 92 and 76. The extra strokes push the progression back round to G.

Rolling the chord

[Chord Sequencer Pitch]    ──> [Electric Piano Pitch]       (poly, 5 channels)
[Chord Sequencer Gate]     ──> [Electric Piano Gate]
[Chord Sequencer Velocity] ──> [Electric Piano Velocity]

With Strum at 25 ms, the five notes of a chord start 25 ms apart, so a stroke takes 100 ms to cross the strings. That's fast enough to hear as one chord, and slow enough to hear it ring out from one end. Alt sets which end: a downstroke starts on the bass note and an upstroke on the top note.

Taper at 40% gives the first note of each stroke the step's full velocity, and each later note a little less, down to 60% for the last. A downstroke lands hardest on the bass, and an upstroke on the top strings. The Electric Piano's tine gets quieter and less bright as its velocity drops, so the shading is easy to hear.

Gate at 60% lifts each note a little before the next stroke, as the strumming hand damps the strings in passing. At 100% every chord would ring into the next, and the rhythm would blur into a pad.

Voicing like a guitar

The roots are written where a guitar's bass strings play them: G2, F♯2 (under the D, as a slash chord), E2 and C2. With Bass voice on, the first channel plays that bass note, and the other four play the chord above it. Spread voicing raises every other note an octave, so the chord spans two octaves, much as an open chord does on a guitar's neck:

Voice lead keeps the top notes moving by step: B, A, G, G, a line that falls with the bass. Cadd9's root is written as C2 rather than C3. As C3 the bass would double the C3 in the chord, and it would land well above the E2 before it. As C2 it ends the walk down an octave lower, under the whole chord.

The porch

[Clock Gate]  ──> [Trigger Sequencer Clock]
[Clock Reset] ──> [Trigger Sequencer Reset]
[Trigger Sequencer Gate 1 / Vel 1] ──> [Drum (Kick) Trig / Accent]
[Trigger Sequencer Gate 2 / Vel 2] ──> [Drum (Shaker) Trig / Accent]

Someone on the porch keeps time with their heel, and someone else plays a shaker. The Trigger Sequencer takes the same eighth-note Clock as the Chord Sequencer, and its 16 steps are the same two bars, so each pad sits under one stroke of the hand. The Clock's Reset goes to both sequencers, so they start the loop together every time Run is ticked.

The second bar is the same, with the downbeat stomp at 74.

The stomp is a heel on wooden boards: a Kick tuned up five semitones, to about 64 Hz, with a short Decay. Snap at 30% makes the pitch fall less, so the hit is a round thump, and it leaves a little knock of wood in it. Tone at 45% adds enough drive for the thump to be heard on small speakers. It lands on 1 and 3, and its velocity, through the Drum's Accent, makes the first beat of the bar a little heavier than the third.

The shaker is the Drum's Shaker: a band of hiss around 7 kHz whose grains swell in over a few milliseconds, as the beads arrive, rather than striking like a hat. Snap at 60% lets the beads rattle a little inside each grain. Each step is a ×2 ratchet, two grains evenly spaced across the eighth, so an eighth-note lane plays sixteenths. Its velocity follows the strum: 60% under a downstroke and 82% under an upstroke. The softer grains swell in more slowly too, as a looser wrist does. A shaker player's wrist pushes against the guitarist's, so the offbeats lift where the piano's strokes are lightest. The shaker keeps going through the tied steps, where the hand moves without striking.

The room

[Electric Piano Out] ──> [Chorus In L]
[Chorus Out L/R]     ──> [Mixer Ch 1 / Ch 2]   (panned hard left and right)
[Drum (Kick) Out]    ──> [Mixer Ch 3]
[Drum (Shaker) Out]  ──> [Mixer Ch 4]
[Mixer Out L/R]      ──> [Reverb In L/R]
[Reverb Out L/R]     ──> [Tape In L/R]
[Tape Out L/R]       ──> [Audio Output Left/Right]

A light chorus widens the piano into stereo, as two microphones would a guitar. The Mixer seats everyone in one room: the chorus's two sides panned hard left and right, so the piano keeps its width and its level, the stomp in the middle, and the shaker a little to the right, where its player would sit. The drums join after the chorus, so its short delays don't smear the thump. A small room with a short decay keeps the strokes distinct, so each one is heard, and it gives the stomp a little space around it. The Tape at 15 ips adds a little warmth and sway, and enough hiss to hear between the chords.

Variations

Push the change. Set step 8 to Em7 (right-click it: root E, type m7). The Em7 now comes in on the last upstroke of the bar before, an eighth early, as a rhythm guitarist often plays a chord change. Do the same on step 16 with G to push into the top of the loop.

Every stroke down. Set Strum dir to Up, so every stroke starts from the bass, and Gate to 30%. It's now a chugging eighth-note rhythm, as a punk band plays it.

A four-on-the-floor heel. Add the stomp on steps 3, 7, 11 and 15 too, so the heel comes down on every beat, and the porch turns into a hoedown.

A looser shaker. Ctrl + click a few of the shaker's pads to play only 75% of the time. The shaker stops sounding like a loop, and the strum stays the same.

Just the guitar. Mute the Mixer's channels 3 and 4 to hear the strum on its own, as the patch was first written.

A stroke of your own. Right-click step 4 and set its Strum to Up. That upstroke turns into a downstroke on the "and" of 2, an accent against the beat. Under Alt, the hand keeps time around it, so the rest of the pattern doesn't change.

More or less dig. At Taper 0 every string sounds equally, which is stiffer. At 80% the strokes just catch the first few strings and fade before the others.

A slower hand. Raise Strum to 50 ms for a lazy strum. At 80 ms with Strum dir on Up, a chord rolls upward like a harp.

Another instrument. Swap the Electric Piano for the Library's Mallet or String Machine. The strum works on any voice. Taper shows most on a voice that gets quieter as its velocity drops, as the Electric Piano and the Mallet do.

Related

• Chord Sequencer – Strum, Taper and a step's own stroke, in detail
• Groups and the Library – the Electric Piano and the other voices it can swap for
• Trigger Sequencer – ratchets, velocity and the lanes the porch plays
• Roll Call – a whole kit on one Trigger Sequencer
• Afterglow – the Chord Sequencer playing a pad and moving an arpeggio
• Clair de Satellite – an electric piano comping in a whole song