The presence of 'however' in statement 4 suggests that 4 must be preceded by a contrary idea. Statement 1 has that. Thus 1 and 4 form a mandatory pair. 3 says 'your tune may change'. In other words, 'your attitude may change'. That attitude is there in statement 1. Thus 143 form pair because 3 cannot come before 1 . You must state the negative attitude, and then say that your attitude may change after you realize the amount of skill required to come or perform such music. Statement 2 can come only at the start and not at the end. Thus 2143 is the right sequence. An easy question.