Features

Pocket Orchestra has two modes - Tuner and Scale Builder. This page will go into depth on both.

Tuner

Scales can be loaded from file on this screen. If no .scl or .scale files are found in the scale folder, Pocket Orchestra automatically uses a 12-tone equal tempered scale. Users can temporarily edit the fundamental frequencies of their scales - this allows for quick transition between (for example) A = 438 Hz and A = 440 Hz equal temperament, without creating an entirely new scale file. Users can also specify which note should act as the fundamental. This way (for example), an F just scale and a G just scale can be stored in the same file and edited whenever it comes time to tune. Pocket Orchestra automatically calculates the standard A = 440 Hz pitch for these notes so you don't have to; however, the pitch is also fully customizable.

After the scale is loaded and the optional additional settings are specified, pressing "Set and Tune" begins the actual tuning process. The tuner uses autocorrelation hand-in-hand with a precise quadratic approximation to give results accurate at frequencies as high as 8000 Hz (to within 2 Hz). At more common frequencies, results are reported accurately to at least two decimal places. Pitch data is reported every quarter second in a minimal and color-coded display. Green text means that the pitch is approximately in tune, yellow and red mean that the pitch is going sharp or flat. The rate at which the text turns from green to red is directly proportional to how far apart the notes are spaced - everything changes dynamically to the loaded scale.

Scale Builder

At the start of the Scale Builder wizard, users can specify whether they want to build their scale from scratch or edit an existing scale (sometimes using it as a template). Users can specify the names of notes, their relative pitch in cents, their ratio to the tonic frequency, and their absolute pitch in Hz. All the math required to convert between these data types is automatically computed by Pocket Orchestra - no calculators needed! In addition, tools to automatically set the scale to X-tone equal temperament and to sort the scale are provided. Scales save to either the .scl or .scale format - no preference. Pocket Orchestra ensures that any scale saved using the Scale Builder will be compatible with the Tuner mode.

Tips For Best Use

• Cents are always given as 1/100 of a step in the 12-tone equal tempered scale.
• The tuner works on the assumption that the signal it is tuning is highly periodic and is sustained for a quarter of a second or longer. To ensure the reading is accurate, hold the note to be tuned at a volume significantly louder than the background noise of the room. If the room is extremely noisy, it might be wise to move to a quieter place.
• Pocket Orchestra is constantly interacting with the scale folder. Any .scale files or .scl files stored in that folder will automatically appear on the dropdown menu that selects the scale to load. Simply click one of the modes on the top bar to reload the scales from file. To prevent slowdowns, only the first fifty scales are loaded into Pocket Orchestra. It is recommended that all unnecessary scales are stored in a subdirectory in the scale folder and only placed in the actual scale folder when necessary.
• The tuner is able to work extremely efficiently because of two assumptions - the scale is ordered in ascending pitch order, and the scale is contained within one octave. If the scale you wish to tune is out of order, Pocket Orchestra will order it for you without changing the actual content of the file. If you are using the .scale format, Pocket Orchestra will report to you the note names you saved. You won't even know the difference! Scales that are larger than one octave are not compatable with Pocket Orchestra. If there is considerable demand for this particular feature, I will go through and rework the math in a later update.
• Press stop tuning when you are done tuning your instrument! Otherwise Pocket Orchestra will use some of the computational resources of your computer that are better spent elsewhere.

For more information on how Pocket Orchestra works, particularly on the math of the tuner, visit the how it works page.