As for your other question, Kevin @kjlarochelle, the answer is yes. other notes can be played. In fact any note of the chromatic scale can be played – the real question and the art of making music involves the when, where and how these other notes are used in the solo. Much depends on the “musical context” i.e. the notes played just before and just following the place where you wish to use some other note. Perhaps not the best analogy, but it is similar to speaking/writing in some language: basically any word of the language can be used, but depending on the context it can result in nonsense, or an insult or be perfect in that context.
What is “safest” is to play the notes of the scale (in this case Gmin). The other notes usually sound best when played as “passing notes” (notes not played slowly but sort of quickly inserted when moving from one scale note to another). Another rule of thumb is to play those other notes on the “off-beat” (because they are then “less noticed” by the listeners).
This is all something that you also learn through experience, trying it out and seeing/asking if the resulting effect works or is what you intended. To this end it is very usefull to record your playing (ideally with a simple accompaniment, such as an acoustic guitar, rather than in a group situation where it is more difficult to hear what you have played – but playing alone also works). 
Regards,
– Slim 