The most current version of SmartMusic has limited support for guitar. Both guitar and electric bass are usable but there is a very small amount of repertoire available for these instruments. Some method books and the built-in exercises have these instruments available based on what instrumentation was available from the method book's publisher.
SmartMusic has support for MIDI keyboard, where the electronic keyboard is connected to the computer through a MIDI interface. However, you would not be able to place a microphone near a piano and use the program.