Audacity is a free, open source software for recording, mixing, and editing sound. Although it is not nearly as sophisticated (or expensive) as something like PRO Tools, Audacity is a decent editing and mixing piece of software. It is also reasonably easy to use. Contained within the list of features and functions in Audacity is the ability to change tempo and pitch. Although Audacity does perform these functions, the quality of the resulting audio is not particularly good. Tempo change (slowing down or speeding up) can be accomplished independently of pitch, but as you decrease the tempo you quickly begin to hear artifacts and distortion with decreasing tempo to the point that the result audio is unusable.
Pitch or key change is even more problematic because changing the pitch in Audacity changes the tempo... so the pitch change feature is not independent of tempo, which makes it almost unusable.
A much better way to change music, song or audio key is with Song Surgeon. There are two different ways to accomplish this with Song Surgeon. One is with our desktop software, which costs money, and the second is with our free online service. Let's briefly review both.
The Song Surgeon online pitch and tempo change is free and, more importantly, the sound or audio quality of the pitch and tempo changes is superb. This web-based service utilizes the same sound engine found in the Song Surgeon software, and it has equal or superior sound quality to everything to which we have compared it.
Song Surgeon is also available as a software application for both Windows and Macs. Version 3.0 of Song Surgeon is available in both a Standard and a PRO model. Version 3 contains the sound engine used in the online version that is responsible for the unsurpassed audio quality. In fact, the desktop version contains 2-time stretching algorithms to accomplish pitch and tempo change - one for small changes, such as changing key by ½ step. This is called the P, or performance, setting. The second setting is known as the T setting (Transcribe) and is used for more extreme changes, such as slowing the audio to 30% of the original to assist with transcribing a song or a difficult solo.These two settings maximize sound quality and provide distortion-free audio even at extreme changes.
While the slow down technology remains the most commonly used feature found in these types of programs, and musicians remain the most common users, the new version of Song Surgeon with its many new functionalities will certainly open the door to use in many other fields such as dance, exercise classes, transcription, karaoke, translation, and worship music, to name a few.
While there has been some discussion and suggestion of augmenting and modifying Song Surgeon's capabilities to include recording and mixing, like Audacity, this is not currently being contemplated for the next version.
The bottom line is that if you are looking for software for recording and mixing, then Song Surgeon is not for you. But, if you are looking for a top-notch, slow-down software that is best-in-class, then Song Surgeon is that product. The limited and poor quality of these functions in Audacity doesn't even merit comparison, unless your budget is $0. In that case we still wouldn't suggest Audacity; rather, download and use the Song Surgeon demo or use the online version which is free.
Song Surgeon provides a 4-hour fully functional working demo. Four hours may seem like a lot of time, but we caution you to close the program when not using it to preserve this time. We also suggest that you watch the training videos found on the website before using the program, as these will help you get up to speed quickly with the operations of this very useful software.You can download the DEMO version from here.