# Arco content changelog, references and practice tools

Read dated changes to Arco’s free music references and practice tools, with the limits of each addition stated plainly.

Updated: 2026-08-31

## August 31, 2026, instrument tuning references

Added separate violin, viola, cello and double-bass tuner pages. Each starts with the matching instrument, lists the open-string sounding pitches and explains common octave-reading mistakes. Reference tones work without an account or microphone permission; the optional meter listens on the device.

## August 31, 2026, printable string charts

Added a reference page for each of the four strings on each instrument, with selected first-position notes, an original practice exercise and a downloadable PDF. The four whole-instrument charts also have direct PDF downloads. Upper positions, extensions, half position and thumb position are not covered by these sheets.

## August 31, 2026, public scale references

Added free scale pages derived from the supported Technique Gym routines. Written pitch tables remain available before the optional notation and audio player loads. Available keys and octave ranges follow the actual routine data; the double-bass selection is narrower and uses sounding pitch. Missing fingerings are identified instead of guessed.

## How to read this log

Entries describe the content available in this version of the site. A Preview may contain changes before the public production site receives them. This log does not certify a search-engine crawl, indexed status or ranking, and its dates do not refresh automatically on deployment.

## References and next steps

- [Instrument tuners](/tools/tuner)

- [Charts and PDF downloads](/charts)

- [Scale references](/learn/scales)

- [Method and evidence limits](/method)

- [Report a correction](/contact)

Canonical source: https://arcosounds.com/changelog