Invisible Lines makes an apropos title for the solo debut from JM Stevens. The Austin- based songwriter who fueled Moonlight Towers through 15 years, four albums and thousands of miles crisscrossing the country on shoestring tours has a knack for tapping the intangible elements of pop songcraft that elevate the enduring from the ephemeral.What Stevens leaves out of his songs is almost as important as what he puts in. There’s no instrumental derring-do or insular lyricism. He’s wise enough to know not to let musical ego get in the way of a good hook. Stevens would rather have you humming along and connecting with the songs on your own emotional terms.