Elsa is a retro style sampling keyboard that offers a range of features for music enthusiasts. With its on-screen keyboard or the option to connect your own MIDI device, you can record, save, load, and even reverse samples. The program also comes with three built-in effects - reverb, resonant filter, and sample rate/bit crusher - to add depth and texture to your samples.

One of the standout features of Elsa is its tempo-based looping. You can loop your samples in three different modes - one-off, forward, and forward-reverse - allowing for creative and dynamic compositions. Additionally, you have control over the start and end points of playback, with options to set them for all notes, per note, or per octave.

Elsa supports various audio connections, including AudioCopy, AudioBus, Inter App Audio, and AUv3. This makes it easy to integrate Elsa with other music production apps and devices. Furthermore, all audio parameters can be modulated by MIDI, giving you even more control over your sound.

Overall, Elsa offers a comprehensive set of features for sampling and music production. Whether you're a beginner or an experienced musician, this retro-style keyboard is sure to inspire creativity and enhance your music-making process.