Sienna's "Grey " is the kind of track which is purely soothing to the ears. Particularly because of her voice which sits well in the forefront of the mix, and is easily one of the most lush sounds I've heard in a while.
I say 'thought-provoking' as their reflective nature acts a gateway for us to think of the workings of our relationships and loved ones. The neo soul and r&b infusion makes for a perfect track to play during pillow talk.
Her vocals actually remind me of the lead singer of Submotion Orchestra and if that's something you fancy, this is bound to be your cup of tea.