Poor Ryan! it IS a frustrating age because they are JUST about doing so many fab things! i would say look for ways of supporting Ryan to do what he can, maybe you could borrow a bumbo seat so he is doing more sitting work, maybe one of those baby nests or just some pillows behind him will do the trick for sitting! Failing that, i bet he would love bouncing on your knees in a sitting position (which will also bring on tummy and back muscles for sitting)
remember when he is sitting, balance will be harder so you may need to take a step back with things to handle and offer toys on an activity arch that can be pushed or that make noise rather than things to pick up and grab.
you can do lots of tummy time as it will come in handy for crawling and do some fun moving about.
songs are great, especially ones with actions that you can do or that you can move him through.... stories are great too
i would keep going but could be rumbled anytime as am at work! HTH! let us know how you are doing!
x