djay is the pre-eminent dj software for the Mac because it's as easy as iTunes but way more fun. It's loaded with dj-centric features like harmonic mixing and on-the-fly audio analysis but it's also easy to just drag-and-drop tracks from your iTunes library to get the party started.
New in djay 4.0:
Harmonic mixing makes it easier to find songs that go well together. djay performs precise beat, tempo, volume and key analysis on your tracks so that you can not only match tracks by BPM and loudness -- but also by key/pitch. djay 4's advanced key detection (including distinction between major/minor key) allows you to filter and sort your iTunes library by key for harmonic mixing -- great for making chart-topping mashups of songs from your library.
Tracks are automatically analyzed when loaded onto a turntable, or you can analyze a playlist or your whole library by selecting Library > Analyze. To filter your library by key, select the treble clef in the library selector. djay 4 organizes keys in a circle of fifth to allow you to quickly find songs with similar keys. Songs within the same key match best and are best for mashups.
In the case where two songs have different keys, djay allows you to automatically match the key of one song to the other in the key popover:
djay 4.0 also includes a bunch of fly new DJ tools which are revealed by clicking the triangle underneath the crossfader. A new drawer is displayed that hosts lots of cool new audio effects. Here you can toggle between three different FX styles with the up/down arrow buttons.?
Easily my favorite feature is djay's 2D FX pad (below). It allows you to control multiple song parameters in real-time and it's absolutely killer with the trackpad in my MacBook Air (and with the Magic Trackpad). Simply drag two fingers across the trackpad and experiment on your favorite song. Don't forget the right/left arrow to jump between echo, reverb, gate and the others, it's a blast.
djay's enhanced bounce loop mode allows you to mash up beats on the fly without losing the timeline.
A completely new live sampler is accessible by clicking the sample button in the center. It allows you to manage your sample collection and create new ones on the fly. djay 4.0 comes bundled with a high-quality sample pack that greatly improves the out-of-box experience with the sampler.
djay 4.0 also features enhanced pre-cueing, auto mix, MIDI control and several new hardware configuration options (output, headphones, mic). Add it all up and you've got some amazingly powerful DJ tools at your fingertips. Wether you're a weekend warrior or semi-pro mashup artist djay 4.0 for Mac has something for everyone. With djay, the best just gets better.
New Features Overview:
- Redesigned single-window UI (OS X Lion style) - iCloud integration - Visual Waveforms - Harmonic mixing: key detection, key transposition and key matching (create mash ups of songs in perfect harmony) - New Auto-Gain/Audio Normalize based on the Loudness Recommendation EBU R128 standard - New Audio FX: Gate, Flanger, Phaser, Reverb, Echo, Filter (Low Pass + High Pass) - Instant FX: Absorb, Drift, Sway, Crush, Punch, Twist - XY Pad FX - New integrated Live Sampler - New audio engine: high quality key lock, low-latency scratching - New stunning OpenGL graphics engine - New loop modes: Bounce looping - Advanced CoreMidi integration and MIDI learn including jog wheel mapping - Enhanced Audio Hardware support and configuration options: Master Output, Pre-Cueing, Microphone (+ Split Output Mode) - Improved Library integration: integrated history, support for playlist folders, improved sorting, integrated key info, on-the-fly table column re-arranging - Dark/Light library themes - Built-in organizer of recordings with instant preview - Enhanced Mic - Enhanced Pre-cueing - Enhanced Automix
Update: Here's a video of the djay 4.0 in action: