Install the Chrome extension.

Then, navigate to http://www.musictheory.net/exercises/ear-interval for some ear training interval exercises.

Press ENTER to hear the interval again. Press 1 to select Unison. Press Down-2 to select Minor Second. Press 2 to select Major Second. Press Down-3 to select Minor Third. Press 3 to select Major Third. Press 4 to select Perfect Fourth. Press Down-5 to select Tritone. Press 5 to select Perfect Fifth. Press Down-6 to select Minor Sixth. Press 6 to select Major Sixth. Press Down-7 to select Minor Seventh. Press 7 to select Major Seventh. Press 8 to select Octave.

This Chrome extension is based off of the template available at https://github.com/salsita/chrome-extension-skeleton.

I've included the relevant instructions for developers from the template project here.

git clone git@github.com:dbieber/interval-training-extension.git

# in case you don't have Grunt yet:
sudo npm install -g grunt-cli

cd chrome-extension-skeleton
npm install
grunt

/build             # this is where the extension (.crx) ends up,
                   # along with unpacked directories of production and
                   # develop build (for debugging)

/code
    /images        # image resources
    /js            # entry-points for browserify, requiring node.js `modules`

        /libs      # 3rd party run-time libraries, excluded from JS-linting
        /modules   # node.js modules (and corresponding mocha
                   #   unit tests spec files)

    manifest.json  # skeleton manifest file, `name`, `description`
                   #   and `version` fields copied from `package.json`

Gruntfile.js       # grunt tasks (see below)
circle.yml         # integration with CircleCI
crxmake.sh         # official build script for packing Chromium extensions
mykey.pem          # certificate file, YOU NEED TO GENERATE THIS FILE, see below
lint-options.json  # options for JS-linting
package.json       # project description file (name, version, dependencies, ...)

• clean: clean build directory
• test: JS-lint and mocha test, single run
• test-cont: continuos test loop
• default: clean, test, build step (copy all necessary files to build directory, browserify JS sources, prepare production version (using uglify), pack the crx (using official shell script), and copy the resulting crx to CircleCI artifacts directory (only when on CircleCI))

1. Generate your .pem key and store it in the root as mykey.pem file. On unix / mac, the command to generate the file is openssl genrsa 2048 | openssl pkcs8 -topk8 -nocrypt > mykey.pem. Note: the generated file is in .gitignore file, it won't be (and should NOT be) commited to the repository.

2. Add content, updating code/manifest.json accordingly.

3. When developing, write unit-tests, use test-cont Grunt task to check that your JS code passes linting tests and unit-tests.

4. When ready to try out the extension in the browser, use default Grunt task to build it. In build directory you'll find develop version of the extension in unpacked-dev subdirectory (with source maps), and production (uglified) version in unpacked-prod directory. The .crx packed version is created from unpacked-prod sources.