Using Prism

If you haven't already gotten familiar with how to get audio into Prism (for ARA, just adding Prism to the track is all you need to do; for non-ARA, you have an extra step of capturing the audio first), please refer to Introduction for details.

Prism Interface

To get the most out of Prism, you'll need to be familiar with its interface and the features and abilities it provides.

Top Bar (ARA mode)

1. About - display version and license info
2. Track selector - if Prism has been added to multiple tracks, you can switch among them using this dropdown.
3. Follow DAW selection - when enabled, Prism will automatically switch to the track that is currently selected in the DAW.
4. Algorithm selector - this selects the algorithm that Prism uses to determine what notes are playing and convert them into midi. Select the algorithm that best represents your audio. When changing the algorithm, Prism will automatically begin processing the audio with it.
5. Re-analyze audio - Use this if you've modified the midi in Prism's midi editor and want to go back to the original analyzed audio.
6. Snap selector - the snap setting used by Prism's midi editor
7. Loop toggle - control looping during playback

Top Bar (non-ARA mode)

1. About - display version and license info
2. Capture Audio - this button is used to "arm" Prism for capturing the audio when the DAW starts to play. Once audio capture has started, click this button again to stop capturing.
3. Algorithm selector - this selects the algorithm that Prism uses to determine what notes are playing and convert them into midi. Select the algorithm that best represents your audio. When changing the algorithm, Prism will automatically begin processing the audio with it.
4. Re-analyze audio - Use this if you've modified the midi in Prism's midi editor and want to go back to the original analyzed audio.
5. Snap selector - the snap setting used by Prism's midi editor
6. Undo & Redo - undo and redo midi editing actions
7. Settings - display the settings (change colors and mouse behavior)

Under the top bar is the Bar track

Bar Track

The Bar Track displays the bars for the audio in Prism. In ARA mode, you can create a loop by dragging in the top-half of the bar track.

Waveform Track

The Waveform Track shows the audio waveform for all the clips in the track that Prism is assigned to, along with controls for playback and displaying content in the editor view.

1. Shows the Track name assigned in the DAW

2. The first button enables playback of the original audio. The second button enables playback of the midi notes through Prism's built-in piano sampler. The third button displays controls for adjusting the audio and midi volume levels and panning.

These controls are useful if you want to ensure an accurate midi transcription. By disabling Audio playback and enabling Midi playback you hear the midi results re-synthesized as a piano (keep in mind that Prism's piano sampler is very rudimentary and any plugin Instruments you have will likely sound much better).

You may find it useful to enable Audio playback but pan it to the far left, and pan the Midi to the far right--best to wear headphones when doing this.

3. The third row of three buttons control what is displayed in the edit area. In order these buttons are:

• SPEC - displays spectrogram of the audio track. This is sometimes useful to get a finer view of pitch contours than midi notes and make things like vibrato and pitch bends visual.
• PITCH - this is essentially a processed spectrogram that has detangled and assigned the overtones to individual notes. It is sometimes useful to compare it with the midi notes and may make it easier to find missing midi notes.
• MIDI - the midi notes. These notes are fully editable, you can move, change duration, add, and delete them.

Deleting an Audio Clip

In ARA mode, deleting an audio clip in your DAW will remove it from Prism.

In non-ARA mode, delete an audio clip in Prism by right-clicking on the clip and selecting "Delete Clip" from the pop-up menu.

The Editor

The editor area consists of a few controls and an area to edit the midi notes.

1. "?" - This is just a handy tooltip that displays various methods to scroll and zoom within Prism's editor. (It would really be nice if there were standard agreed upon controls/keys for zooming and scrolling that every DAW would use!).

2. Drag MIDI - just click on this button and drag-n-drop it into your DAW to add the midi to your project. Click SAVE MIDI to save the midi to an external midi file.

3. Sensitivity - this knob gives you some degree of control over how strict Prism is in declaring midi notes. Higher values make the algorithm more selective about notes and will result in fewer notes displayed, while lower values will add in more notes. Double-click the control to reset back to the default sensitiviy setting for the current algorithm.

In the video below, we slowly change the Sensitivity knob. Notice how notes dissapear at higher sensitivity values and are added as senstivity is decreased.

Using the Editor

The midi editor works like every other midi editor. To see a list of commands, right-click in the editor.

In this short video, we use the mouse to select a group of notes, then right-click and select Quantize Notes.

Key and Mouse Actions

Action	Mouse/Keys
Pan/grab	Ctrl + Shift + left-mouse-drag
Scroll horizontally	mouse-wheel or trackpad swipe left/right
Scroll horizontally	←, →
Scroll horizontally	bottom scrollbar
Zoom horizontally	Shift + mouse-wheel or trackpad pinch
Zoom horizontally	↑, ↓
Zoom horizontally	zoom-slider to right of bottom scrollbar
Zoom vertically	Ctrl + Shift + mouse-wheel or pitch
Zoom vertically	zoom slider below vertical scrollbar
Zoom into a specific region	Ctrl + Alt/Option + mouse-drag rectangle to zoom into
Add midi note	Alt/Option + click

• Note: You can change the scroll-wheel direction and action (scroll or zoom) in Settings.

Use the Approprite Algorithm

Prism has three algorithms to get the best results for a given audio recording. Selecting the best one is usually trivial based on the instrument in the recording.

• general - this is the algorithm to use unless you specifically have content addressed by one of the other algorithms. It will analyze both mono and polyphonic data sources and is the one to use for acoustic guitar, clean guitar, bass, keyboard type instruments, saxophone, trumpet, violin, etc.
• dist guitar - distorted guitars are problematic due to the large variance in overtones that distortion effects generate so it gets its own algorithm.
• ac piano - use this algorithm if you are processing high quality solo acoustic piano performance. If your track contains a piano stem that has been separated from a mixed track or a lower quality piano, then general will probably give better results.

Changing Color of Waveforms and Midi Notes

For ARA mode, the color of the waveform and midi notes are determined by the DAWs track color. So to change the color Prism uses, simply change the track color in the DAW.

For non-ARA mode, select colors for the waveform and midi notes in the Settings dialog.