I am interested in learning concurrent programming, focusing on the application/user level (not system programming). I am looking for a modern high level programming language that provides intuitive abstractions for writing concurrent applications. I want to focus on languages that increase productivity and hide the complexity of concurrent programming. To give some examples, I don't consider a good option writing multithreaded code in C, C++, or Java because IMHO my productivity is reduced and their programming model is not intuitive. On the other hand, languages that increase productivity and offer more intuitive abstractions such as Python and the multiprocessing module, Erlang, Clojure, Scala, etc. would be good options. What would you recommend based on your experience and why?