Jam-a-Lot User Manual

1. Playback & Live Performance Controls

Transport Controls

Located at the top of the interface:

• Play / Stop / Pause: Controls the playback state.
• Count-in: Select between 1 or 2 bars of count-in.
• Metronome: Toggle a metronome click on or off.
• User Menu: Sign in via Google OAuth or Email/Password, manage cloud library sync, give feedback via the Feedback modal, and view active user preferences.

User Account & Preferences Menu

• Join Beta Program / Account Button: Labeled "Join Beta Program" (with sparkles icon) when signed out. Toggles user profile menu when signed in.
• Guest Mode Notice Banner: Persistent notification explaining Guest Mode (3 demo tunes: Blues in F, Oleo, & Mr. P.C.).
• Cloud Library Sync: Back up custom charts and preferences to your personal Supabase account across browsers and devices.
• Give Feedback: Submit bug reports, feature requests, sound quality feedback, or general comments with interactive star ratings.

Bandstand Stage

The animated band graphic above transport controls allows screen theater mode expansion. Hotspot labels (bassist, drummer, comping style, room) cycle settings on click.

Performance Panel

Located directly below the transport. Split into four core tabs:

Practice Routines

Click the dedicated Practice metronome icon in the top row. Build major or minor ii–V–I cadences, major or minor turnarounds, dominant cycles, or the reviewed four-bar Coltrane Countdown cycle. Choose a starting key, 1–12 key stops, 4 or 8 bars per key, tempo, and either a fixed semitone step (default +1) or random steps through distinct keys.

Load the chart and press Play. It is saved in the Practice collection as a regular tune, so Performance Plan chorus counts, solos, drum trading, Living Changes, the mixer, and tune editing all work. Rebuild refreshes the chart; Return to previous tune takes you back when available.

Solo Rhythm — Following the Form or Opening Up

Salsa bell drive: In Performance Plan → Rhythm, each Salsa section can keep its normal two-hit bell, use Loose quarter notes for four hits with an alternating eighth-note pickup, or use Quarter-note drive for four even hits. An explicit drive choice brings in the bell even at quiet energy levels; clave, tumbao, and tempo remain unchanged.

Under solos, choose whether the rhythm section follows the written form or switches to a single style (e.g. Swing) after N choruses:

• Follow written form: Every solo chorus plays section rhythms as written.
• Switch to [Feel] after N choruses: Plays written form for N choruses, then switches to selected feel for remaining solo choruses.

2. Chord Chart Views

Jam-a-Lot offers multiple layout modes to suit your practice setup:

• Standard Grid: Classic 4-column layout mapping bars evenly.
• Extended View: Authentic real-book lead sheet notation replacing grid lines with traditional bar markings, with every pass of the form written out in full.
• Repeat View: Collapses repeating sections using standard musical repeat brackets (|: and :|). First and second endings — written with 1/2 markers in the text editor, or inferred from two similar passes — fold into one body with numbered brackets after it, and the bracket that is coming up next lights up as playback enters that pass.
• Vintage View: Amber monospace layout displaying full form without repeat folding.

Interactive Bar Seeking & Custom Range Looping

• Click to Play / Seek: Click any bar in the chord chart while stopped to start audition playback immediately from that exact bar without count-in delay. This includes the displayed intro and ending: an intro click stays in the intro, and an ending click stays in the ending. Click any bar while playing or paused to jump transport directly to that bar.
• Shift+Click & Drag Range Looping: Click a starting bar, then Shift+click an ending bar (or drag across bars) to highlight and continuously loop over that section.
• Loop Banner & Controls: Displays active loop range info with a ✕ Clear button (or press Esc) to cleanly return to full form playback.

Section Color-Coding

• Section A: Sky-blue
• Section B: Mint-green
• Section C: Soft-violet
• Section D: Warm-amber
• Section E+: Dusty-rose

3. Instrument Mixer & Quick Controls

Out of the box, all three instruments play at a calibrated level (expressed in decibels dB).unity 0.0 dB represents the calibrated baseline.

Stage Plot & Stereo Panning

Importing Custom Piano Samples (SFZ)

1. In Piano card, click Import samples….
2. Select both your .sfz file and referenced .wav files together.
3. Audition C4 and click Import Kit. Saved to browser IndexedDB automatically.

4. Rhythm Styles & Bossa Nova Fine-Tuning

Jam-a-Lot separates feel, rhythm style, and mixer sound. Accompaniment families include Swing, Ballad, Gypsy Jazz, Bossa Nova, Latin, Bolero, Tresillo, Waltz, Soul-Jazz, Funk, Blues Shuffle, R&B / Neo-Soul, Rock, and EDM.

Tresillo layers a 3+3+2 rhythm across drum kit and hand percussion: kick and claves accent beat 1, the & of 2, and beat 4; hi-hat and snare keep time while congas answer. Select Tresillo in the rhythm style picker with the standard kit to hear both parts.

Bolero uses an eight-bar piano phrase rather than a repeating one- or two-bar comp: bordoneo and tresillo statements open into partial-cell answers, a deliberate breath, and the full cinquillo at high energy. Each following phrase varies while written chord changes remain clearly stated.

Live Changes (formerly Living Changes)

Toggle Live Changes to reharmonize solo choruses without changing the stored chart. Recognized blues and Rhythm Changes forms use reviewed templates; other tunes receive destination-aware tritone, secondary-dominant, passing-diminished, backdoor ii-V, full tritone ii-V, and major-turnaround substitutions. These cadence rules work whether ii-V is written in one bar or two. Coltrane Cycle now defaults on and fits reviewed major-thirds cycles into complete two-, three-, or four-bar major ii-V-I cadences while preserving the final written tonic. Strict blues may borrow atomic Bird Blues phrases, and strict Rhythm Changes may borrow a complete ii-V-chain or tritone bridge; the Reviewed Library Families toggle controls those shared families. Same-root extensions are color, not Live Changes. Flow plans a stable proportion of compatible changes across the whole phrase: 0% makes none and 100% uses every non-overlapping opportunity.

5. Drummer Avatars & Human Feel

Select preset drummer profiles under Settings → Feel & Variation:

• Philly Joe: Swing-forward, traditional timing, and natural feel.
• Elvin: Loose timing, heavy syncopations, high comping intensity.
• Tony: Driving feel, ride-focused, razor-sharp timing.
• Max: Balanced swing, structured snare fills, melodic flow.

Bassist Avatars

Includes Standard Walk, Jaco, Eddie Gomez, Ray, Paul, and Ron profiles.

6. Library, User Tunes & Fork-on-Edit

Locate standards by title, composer, tempo, or feel with instant search and A-Z jump indexing in the Library sidebar panel.

User Tunes Collection & Fork-on-Edit

• User Tunes & Collections: Organize your tunes into custom folders or gig setlists. Your personal compositions (source: 'user'), imported lead sheets, and custom versions live in the dedicated User Tunes collection or any custom collection you create.
• Moving & Copying Songs: Use the ⋯ menu on any song to move or copy it to an existing or new collection. Moving or copying a built-in or catalog standard automatically forks it into an independent User Tune under the target collection, keeping the pristine public standard untouched.
• Collection Management: Click the gear icon beside any custom collection to rename it across all songs, disband it safely (moving all songs to User Tunes without deleting them), or delete the collection and its songs.
• Fork-on-Edit: Modifying any built-in catalog standard (re-keying, editing chords, changing section titles) automatically creates a personal user fork. The pristine original standard remains untouched in the catalog.
• Reset to Original: Any forked catalog standard displays a Reset option in the text editor to discard custom edits and return to the catalog default.
• Coda directions in text charts: Write to coda at last before a repeated section's first chord to enter the Coda before the final pass; write it after a chord when that chord should sound before the jump.
• Cross-Device Cloud Sync: Your user tunes, collections, and edited catalog standards sync automatically across all your signed-in devices (laptop, tablet, phone).

7. Creating, Editing & Sharing Songs

User Handles & Tune Sharing

Share chord charts, performance arrangements, and custom tunes directly with other musicians:

• User Handles: Set your unique username handle (e.g. @jazzbassist) in the User Menu. Other players can send tunes directly to your handle.
• Share Modal: Click the Share icon (fat curvy arrow) on any active tune:
  • Send to @handle: Transfer tunes directly to another registered user's inbox with an optional note.
  • Share Link: Copy a shareable link (app.jam-a-lot.org/#share=code) for instant browser preview and import.
  • QR Code: Display a scannable QR code on screen for bandmates to scan on their phone or tablet camera.
• Shared Tunes Inbox: Incoming tunes arrive in your top-bar Inbox (indicated by a red badge). Preview the chart before clicking Accept & Save.
• IP Safety Enforcement: User-original compositions retain custom lyrics and melody notes. Catalog standards automatically strip all lyrics and melody data before generating share payloads to preserve IP safety rules.

Typing Chords & Never Losing Work

• Shorthand is accepted: a lowercase root anywhere (dm7 → Dm7, bb7 → Bb7, c/e → C/E), the caret major seventh (eb^7 → Ebmaj7), music-keyboard signs (E♭7, C♯m, C–7), and quality words in capitals (DMAJ7). A lowercase letter on its own is still major — write cm or c- for minor.
• Unreadable symbols are never dropped silently: a typo with no readable root is named in the status bar with its line number, in place of "Valid Chart", and saving asks first — the default is to go back and fix it, because saving would leave that bar empty.
• Unsaved text is kept: the editor saves your typing to the browser as you go and offers it back if you close, reload, or lose the tab before saving. An Undo save button restores the text as it stood before the last save.

Half Bars & Double Bars

Two buttons in the Chord Editor toolbar change how many bars the same chords are spread over — the fix for a chart that came in with the wrong chord rhythm.

• Double bars: Inserts a barline between the chords of every bar, so | Dm7 G7 | Cmaj7 A7 | becomes | Dm7 | G7 | Cmaj7 | A7 |. A bar holding a single chord keeps that chord across both new bars, so the form stretches to twice the bars with the same harmony. A four-chord bar becomes two bars of two.
• Half bars: The reverse — merges each pair of adjacent bars into one, so | Dm7 | G7 | becomes | Dm7 G7 |. Half the bars, same chords, two per bar. Asks for confirmation first; a final unpaired bar is left alone.
• The two are inverses on a one-chord-per-bar chart, and repeat marks (|: ... :|) move with the bars they were drawn on.

Text Mode Editor Shorthand

The Chord Editor opens in text mode by default. Universal lead-sheet syntax:

8. The Listening Band (Microphone Input)

Open Listening in the header row to arm the microphone. The band listens in real time and adapts to your performance.

• Follows Energy: Adjusts band dynamics bar by bar based on your input level.
• Phrase Answering: Fills gaps when you pause your solo line.
• Figure Catching: Locks onto repeated 1-bar or 2-bar rhythmic figures played into the mic.
• FFT Leakage Subtraction: Subtracts the band's audio from mic input bin-by-bin for clean speaker operation.

9. Screen Layout & Full Screen

Supports full-screen performance view (Esc to exit), dynamic chord resizing, and auto-scrolling to keep active bars in view.

10. Background Audio Support

Jam-a-Lot keeps playing smoothly when you lock your screen or switch browser tabs, using Web Audio Web Worker timers for precision lookahead scheduling.