Though there are a number of factors downstream that could lead to problematic playback, a quick thing you can try is changing how the software handles sample data. The samples are the actual sounds that you hear, and they represent the heaviest lifting your computer will do while using our resources. By default, the programs are set to stream samples from your hard drive. But a slower computer or hard drive may have diffifulty with the task. In this case, try switching to RAM Load, which will load all the samples into RAM ahead of time. You'll need a computer with more internal RAM and the program will take more time to launch - but it will solve many of the issues that would otherwise lead to stuttering or erratic playback.

1. Open Sinfonia/RMS Keyboards/RMS Coach

2. Open 'Preferences' (Tools Menu on Windows, Product name on Mac)

3. Go to the Audio Tab

Here you'll find the option to switch between Disk Streaming (default) and RAM Load.

1. Switch to RAM Load

2. Click OK

3. Save/Quit/Relaunch