Writing process

I assume that most people here are either guitarists or bassists. So when you create a new song, do you put down the guitar or bass track first to a click? Or do you use a keyboard to lay down drums and bass tracks? Regardless, the use of a keyboard is almost essential so do you spend some time developing keyboard skills (chord inversions, scales, ..)?

Edit: Loops are pretty popular and do not require the use of a keyboard. I’ll assume by the overwhelming response that most are using loops. Loops are OK but I like using a keyboard because it challenges my musical knowledge and keeps it *fresh* especially when building for instance a bass track and using more than just the roots. But what I like the most about using the keyboard is that it can make your track(s) sound *live*, not so perfect, more unique or personalized. I learned piano many many moons ago and hadn’t played in years and I find myself toying around with scales and inversions. Not planning on taking this to the *next* level really but I’m having fun with it. My .02c