I remember when I started playing in the 70s, I almost exclusively used the listen / repeat method, suffering through dozens of replays by lifting and dropping the phonograph needle in just the right groove on the record. Next was song books, quickly followed by musical notation, which was incredibly easy and accurate. But lately, with anything and everything being available on the Internet, I realized that using notation, for me, has only become a supplement to the thousands of lesson videos. Although I still use every one of the methods I have listed, I would have to say that the number of isolated bass parts online has made learning most classic songs so much easier. So, what is your most useful way to learn songs?