# Tonegrid Scale and Sequence Planner

> Map a scale to a note grid and plan your melody. Inspect the pitches in a configurable Tonegrid scale and turn selected cells into a timed note list.

Part of usefulweb.app (https://usefulweb.app/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://tonegridscaleplanner.usefulweb.app/ (interactive tool at https://tonegridscaleplanner.usefulweb.app/tool)
- JSON API: POST https://tonegridscaleplanner.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://tonegridscaleplanner.usefulweb.app/api/v1/tool)
- OpenAPI: https://tonegridscaleplanner.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://tonegridscaleplanner.usefulweb.app/mcp - tool `tonegrid_scale_planner`

## Inputs
- root (number): Root note (MIDI number) - 48 is C3 and 60 is C4.
- scale (select): Scale
- bpm (number): Tempo (BPM)
- swing (number): Swing (%) - Delays alternate steps, like the Tonegrid swing control.
- rows (number): Melody rows
- steps (number): Steps
- cells (textarea): Selected cells: step,row - One pair per line, counted from 1. Row 1 is the highest pitch; the last row is the root. Leave blank for just the scale.

## Method
- Repeat the chosen scale intervals upward from the root and place the lowest pitch on the last row.
- Sixteenth-note steps use the same tempo and swing timing as Tonegrid. Cells in the same column play together.
- Note frequencies use 12-tone equal temperament with A4 at 440 Hz.

## Limits
- The result shows the first melody cycle only, not an audio rendering or drum sequence. For odd step counts, swing alternates between cycles. Timing assumes a constant tempo.