Radium is described as 'music editor with a new type of interface' and is a music production app in the audio & music category. There are more than 50 alternatives to Radium for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and Android. The best alternative is Audacity, which is both free and Open Source. Other great apps like Radium are FL Studio, Reaper, Ardour and Tenacity.
Audacity is free, open source software for recording and editing sounds. You can use Audacity to record live audio, convert tapes and records, edit sound files, change the speed or pitch of a recording and much more.
FL Studio (originally known as FruityLoops) is a full-featured Digital Audio Workstation (DAW) offering a complete range of professional tools for everything from audio editing and beat creation to advanced arrangement, composition, mixing and mastering.
Ardour is a hard disk recorder and digital audio workstation application. It runs on GNU/Linux, Mac OS X, and Windows. Ardour's intention is to provide digital audio workstation software suitable for professional use.
Logic Pro lets you translate musical inspiration into professional productions. A range of powerful, easy-to-use features puts sophisticated tools at your fingertips, and complete surround support lets you make incredible, immersive music.
Make music online with a powerful set of tools ranging from synthesizers and samplers to mixers, delays, reverb and much more. AudioTool is an advanced, collaborative DAW (Digital Audio Workstation) built for the browser.