7 Instrument Sounds on Keyboard Play: Which to Choose
By Keyboard Play
7 Instrument Sounds on Keyboard Play: Which to Choose
One of the best things about playing on an online piano is that you are not stuck with a single tone. The keyboard in front of you ships with seven distinct instrument sounds, and switching between them takes one click at the top of the page. The same melody you just played can become warm and jazzy, glassy and childlike, or deep and solemn depending on which voice you choose. This guide walks through all seven so you know exactly which one to reach for, whether you are practicing scales, noodling with chords, or learning a tune from the song library.
Before we meet the voices, a quick note on how they actually reach your ears. Every sound here is produced by SpessaSynth, a real-time SoundFont2 synthesizer running on the Web Audio API in its own audio thread (an AudioWorklet). The samples come from the FluidR3 General MIDI soundbank — the same kind of professional sample set used in hardware synths. So when you pick "Marimba," you are hearing actual marimba samples shaped by a real engine, not a rough electronic approximation.
How to switch sounds while you play
The seven voices live in a row of buttons at the top of the keyboard. Click any of them and the very next note you play comes out in that tone — no reload, no setup. A few habits that make switching more useful:
- Try the same short phrase in several voices back to back. The contrast teaches you what each color is good at.
- Combine a voice swap with Octave (the ↓/↑ buttons) when a tone sits too high or too low for a particular tune.
- Use Transpose (←/→) to nudge a melody into a better key for singing along.
- Hit Record, play a line in one voice, then play it again in another and Download the MP3 to compare. The recording is processed locally in your browser and never uploaded anywhere.
With the mechanics out of the way, let's look at each sound and where it shines.
Piano — the dependable all-rounder
The default Piano voice is an acoustic grand sampled from the FluidR3 library, and honestly it is the one you will use most of the time. It has a clear attack, a natural decay, and it responds to how firmly you trigger a note, so loud and soft passages feel musical rather than flat.
Because it does not impose a strong personality, Piano works for almost everything: classical studies, pop accompaniments, chord practice, sight-reading drills. When in doubt, start here. It is also the most honest mirror of your playing — if a passage sounds clean on Piano, it will sound clean on anything.
Rhodes — warm, soft, and unmistakably jazzy
Switch to Rhodes and the room changes. This is the classic electric piano tone — mellow, slightly bell-like on the attack, with a rounded body that sustains gently. It is the sound of soul, jazz, and late-night lo-fi.
Rhodes is brilliant for:
- Slow, expressive ballads where you want each note to bloom.
- Jazz chord voicings and gentle comping patterns.
- Anything where a hard piano attack would feel too sharp.
If a melody feels a little cold on Piano, try it on Rhodes. The warmth tends to forgive uneven timing and makes simple progressions sound sophisticated.
Harp — airy, cascading arpeggios
Harp gives you plucked-string sparkle with a long, floating decay. Because each note rings out and fades slowly, it is tailor-made for rolling arpeggios and broken chords where you want notes to overlap and blend.
This is the voice to reach for when you are working through something like the Canon in D arpeggios, or any passage built from flowing up-and-down patterns. Hold Space to engage the sustain and let the strings ring into each other for a genuinely ethereal wash of sound. Harp also flatters simple melodies by dressing them in atmosphere.
Marimba — bright, woody, and melodic
Marimba is a joy for anything rhythmic and tuneful. The tone is woody and crisp, with a soft attack and a short decay, so fast melodic lines stay clear instead of mushing together. It has a playful, percussive character that makes simple tunes bounce.
Reach for Marimba when:
- You want a light, upbeat feel for a folk or children's melody.
- You are practicing fast runs and need every note to stay distinct.
- A song like Jingle Bells or Ode to Joy needs a fresher, less formal color.
Marimba pairs especially well with the built-in Metronome — its short decay makes it obvious whether you are landing squarely on the beat.
Synth — modern, sustained, and electronic
Synth is a sustained lead tone with a smooth sawtooth-style character that holds as long as you keep the key down. Unlike the decay-based acoustic voices, it does not fade out on its own, which makes it feel modern and electronic.
This is the voice for:
- Contemporary and pop melodies that need a steady, singing line.
- Pads and held chords where you want continuous sound.
- Any time you want a tune to sound produced rather than performed.
Because Synth sustains indefinitely, it is also a great teacher of release control — you will quickly notice how long you hold each note, since the sound only stops when you let go.
Music Box — bright, delicate, and nostalgic
Music Box is the crowd-pleaser. It is high, clear, and twinkly, with that unmistakable delicate charm of a wind-up music box. Simple melodies sound instantly magical on it, which makes it perfect for beginners and for short, singable tunes.
Music Box shines on:
- Nursery tunes and lullabies like Twinkle, Twinkle.
- Seasonal songs where you want a storybook feel.
- Quick little demos you want to sound sweet with zero effort.
If you are just starting out, try learning Happy Birthday on Music Box — the brightness makes every correct note feel rewarding.
Organ — full, sustained, and solemn
Organ is a church-style tone that is full-bodied and continuous. Like Synth, it sustains as long as you hold the key, but its character is richer and more harmonically dense, with a weighty, ceremonial quality.
Organ is ideal for:
- Hymns, anthems, and any melody with a dignified mood.
- Layering held chords into a thick, supporting bed of sound.
- Practicing legato phrasing, since the tone never decays mid-note.
It is also surprisingly fun for dramatic intros and transitions. Hold a low chord on Organ underneath a higher melody on another voice and you have an instant arrangement.
Putting it together: pick the voice for the job
The seven sounds cover a wide emotional range, and part of the fun is experimenting. A loose map to get you started:
- Piano — everything, default choice.
- Rhodes — warm ballads, jazz, late-night mood.
- Harp — flowing arpeggios, atmosphere.
- Marimba — bright, rhythmic, melodic lines.
- Synth — modern, sustained leads and pads.
- Music Box — delicate, childlike, nostalgic.
- Organ — solemn, full, continuous chords.
Don't be afraid to break these suggestions — the only real rule is to trust your ear. Try one of the easy songs and play it through in three different voices; the one that makes you smile is the right one. And when you land on a combination you love, hit Record so you can keep it.
Keep reading
- Play Piano With Your Computer Keyboard — master the key layouts so switching voices never slows you down.
- Easy Piano Songs You Can Play Right Now — a graded list of tunes, each ready to try in all seven voices.
- Record Your Piano as MP3 — capture and compare your different instrument sounds.
- Try a voice on a real tune: Für Elise or Jingle Bells.