It’s in the nature of Jana Horn’s music to creep up on you. Just when you think you’re dealing with some pretty straightforward singer-songwriter fare, she’ll slip in a reminder that something more complex and more interesting is going on just beneath the surface. When it seems like melodic prettiness is the order of the day, a lyrical barb will lodge itself under your skin, or a brief passage of uncanny avant-pop will blindside you. Perhaps this is why her music is so difficult to pin down: her second album, The Window is a Dream (2023), saw her singing compared to Greta Kline, Nick Drake and Broadcast’s Trish Keenan and her sound described as country, jazz and post-folk. All of that is true, but none of it is quite sufficient, because Horn occupies an in-between…