Hear the guide tones of every jazz chord
Guide tones - the 3rds and 7ths - are what define a jazz chord. Guido is the PRO quest mode that drills guide tones over real jazz progressions, from 2-5-1 in C to Autumn Leaves and beyond.
14-day PRO free trial. No charge until trial ends. Cancel anytime.
A gamified ear training app, built by a professional jazz pianist
Earonman trains your ear from your first interval up to advanced jazz harmony. Real grand piano sound, structured curriculum, no ads. Web in any browser, native iOS, Android landing soon. Free to start, no card required.
The feature,
explained clearly
Guido is a PRO quest mode in Earonman that drills guide tones - the 3rds and 7ths of jazz chords. Guide tones are the smallest set of notes that fully define a chord's quality (major, minor, dominant, half-diminished). For jazz comping, guide tones are the skeleton everything else hangs on. Guido trains hearing them over real jazz progressions.
Guide tones over real progressions
Not isolated chords. Real progressions - 2-5-1 in various keys, Autumn Leaves A section, common standard forms. Hear how guide tones connect chord to chord.
Voice leading between chord changes
Guide tones move minimally between chords - the 7 of one chord becomes the 3 of the next. Guido trains hearing this smooth voice leading.
Major vs dominant 7 distinction
The only difference between Cmaj7 and C7 is one note: B vs Bb (the 7th). Hearing this distinction in real time is core jazz skill.
Minor vs half-diminished
Cm7 and Cm7b5 share the same root and 3rd. The 5th and the position of the 7th tell them apart. Guido drills this.
Progressive standard forms
Levels start with two-chord 2-5 movements, build to full 2-5-1 progressions, and eventually cover whole jazz standard A sections.
Notation display on web
Guide tones appear on a real notation staff alongside the audio - so you can read along while you train your ear.
MIDI keyboard input
Connect a MIDI keyboard and play the guide tones directly on the keys. On web you get full notation alongside, plus a click-track for play-along practice in time. On Android you input notes via the keyboard for answers.
Three steps.
Repeated until it sticks.
Hear the progression
A short jazz progression plays - usually 2-4 chords with guide tones in the middle voices. Replay as needed.
Identify the guide tones
For each chord, identify the 3rd and 7th. Guido has a notation-based answer interface where you place notes on a staff.
See the voice leading
After answering, Guido reveals the guide tones, the voice leading between chords, and the Roman numeral analysis of the progression.
Skills you walk away with
Guide tone hearing is the bread-and-butter skill of every professional jazz pianist, guitarist, and improviser. It is the layer that connects chord recognition to actual playing.
Hear chord essence in 2 notes
You do not need to hear all 4 chord tones to know what a chord is. The 3rd and 7th tell you almost everything. Guido trains efficient hearing.
Voice leading by ear
In a 2-5-1, the 7 of the ii becomes the 3 of the V becomes the 7 of the I. Hearing this minimal motion is the core comping skill.
Comping skeleton
A professional jazz pianist comps shell voicings (root + 3rd + 7th) constantly. Hearing the 3rd and 7th means you can hear comping in real time.
Standard form recognition
After enough Guido reps, you start hearing 2-5-1 in any key as a unit, not as 3 separate chords. This is what playing standards by ear unlocks.
Improvise around guide tones
Many jazz improvisers build their lines around guide tones. Hearing them lets you do the same - hear the line spine, then ornament it.
Transcribe jazz faster
Transcribing solos and comping becomes much faster when you can lock onto guide tones and ignore everything else as ornament.
Daily reps.
Compound results.
Guide tone hearing is the single most useful jazz ear skill, and the one most musicians never deliberately train. Daily reps build the professional musician's hearing.
Working pianists rely on this every gig
Every comping decision a jazz pianist makes is rooted in guide tones. Daily reps make those decisions automatic.
Transferable to any standard
Once 2-5-1 is in your ears, you can play any jazz standard by ear because 80% of standards are sequences of 2-5-1 movements.
Voice leading is jazz harmony
Jazz harmony is not a sequence of chords - it is voice leading between chord tones. Guide tones are where voice leading lives.
Compounds quickly
After 2-3 weeks of daily Guido, jazz standards stop sounding like sequences of chords and start sounding like flowing voice leading. The change is dramatic.
Not just jazz musicians
Guide tone hearing is essential jazz ear training. The audience is mostly jazz players, but extended to anyone playing standards.
Jazz pianists
Core comping skill. Hearing guide tones is what makes a comper sound like they know what they are doing, not just playing chord symbols.
Jazz guitarists
Shell voicings (root + 3rd + 7th, or 3rd + 7th rootless) are the bedrock of jazz guitar comping. Guido trains hearing them directly.
Jazz bassists
Walking bass weaves through guide tones. Hearing them makes you write better walking lines and call out changes faster.
Jazz horn players
Improvisers who think in guide tones play stronger lines. The 3rd and 7th are where the chord lives; everything else is ornament.
Singers learning to scat
Vocal improvisation over standards lives on guide tones. Hearing them means you can hit the right note over each chord.
Anyone playing jazz standards
Whether amateur or pro, hearing guide tones makes standards playable by ear, transcribable, and arrangable.
Free forever.
PRO when you want more.
Real free tier, not a trial. Practice Mode is open to everyone with a usable foundation library across Intervals, Chords, Scales, and Jazz Voicings - no daily cooldown.
Built so any serious musician can train their ears forever, free.
- Basic intervals, triads & major/minor scales
- Jazz Voicings game mode
- Practice Mode: free training for core intervals, triads, 7ths, major scale modes and basic jazz voicings
- 3 exercises per 8-hour window
- Basic stats and achievement badges
Or €59.99/year (~€5/mo, save 28%)
- Unlimited exercises (no cooldown)
- All intervals, chord types and scales (incl. 7ths, altered, modes)
- 6 advanced quest modes: Slashmaster, Functioneer, Harmonic Quest, Guido, Hybrid Lab, Polychordist
- Open Mic: answer by singing or playing into your microphone (mobile app)
- Practice Mode: full library of intervals, chord types, scales and voicing categories
- Advanced stats: per-quest-type analytics & session breakdowns
- Weekly Leagues with full history
- Full achievement & badge system
- All 8 instrument sounds (Rhodes, strings, harp, e-guitar, flute, clarinet, French horn)
- Priority support
Cancel anytime. No charge during PRO trial. Card only required at trial start.
What makes this
different
Real jazz progressions
Guido uses actual jazz standard forms - 2-5-1 in keys, Autumn Leaves A section, common cadences. Not isolated chords.
Notation-based answer interface
You place notes on a real notation staff to answer, building the connection between sound, ear, and notation simultaneously.
Built by a professional jazz pianist
Created by Tomas Jochmann, a professional jazz pianist. The Guido curriculum reflects what professional jazz musicians actually drill.
MIDI play-along on web
Connect a MIDI keyboard and play guide tones in time with a click-track. The closest digital analogue to working through changes at the piano with a metronome.
14-day PRO free trial
Guido is part of PRO. The 14-day trial lets you try all 6 quest modes free. Cancel anytime, no charge.
“Earonman is an amazing new tool for musicians of all levels who want to sharpen their ears at home or while travelling. It has been created by a gifted and deeply passionate pianist Tomas, who is open to listen to any of your comments and will surely be expanding the already well-designed program with great material!”
