Whether you’re a seasoned producer or musical novice, understanding and isolating an existing track’s musical components can be very useful. Most DAWs already have features that can help, such as tempo analysis or time-stretching. Veteran developers Zplane’s new app, deCoda (OS X 10.7 or later, Windows 7 or later), bundles together features ranging from tempo, key and chord analysis to pitch-shifting, time-stretch and filtering.
To get started, you simply load or drag-anddrop an audio file (wav, aiff, mp3, wma, flac or ogg) into the window and it analyses it. The workspace has an overview navigation bar at the top and transport play bar at the bottom. The central strip shows a looped section of the track and you can select one of two views: waveform or piano roll. The analysis detects tempo, key signature, chords and song sections, and this information is spread around the workspace including a scrolling timeline that shows the chords. The analysis also generates a frequency view, which forms part of the piano roll window.
Practice
Armed with this you can then do various tasks such as loop specific sections, change the tempo without changing pitch and change the pitch without changing tempo. All rather handy if you’re trying to work out or learn to play parts in a track. On a similar tip, deCoda also includes an onboard synth, providing not only a metronome but also chord and note playback. The chords follow those displayed in the timeline, meanwhile notes can be drawn within the piano roll view to pick out melodic elements. You can balance everything using the fold-out mixer, and play along via a plugin of your choice using the input (deCoda includes a lite version of Amplitube 4). There’s even a rather handy focus filter (see explainer below) to help pinpoint specific sounds in the track. To round things off, there are various export options, including MIDI files and lead sheets in plain text and ChordPro formats.