I really liked the tone of your prototype; there is some kind of calm focus in it. The dark background ties well with notes and earphones and makes and helps to make a focal point to the colors in the image. The good thing about this image is we see the third rule is applied as well because of color lights. The main focal point of the picture leads the viewer to focus on where the purple-pink-yellow light color shines on. It was very clever that you chose the pink-purple color for your slogan, it helps to get a remind in mind about the focal point of your picture.
I would suggest though changing font. The font is good but because of its bold nature, makes it a bit confusing, specially is you focus on word “Universe” it is hard to follow. Maybe less bold would do much better and help you to communicate your message better.
Also you have the advantage of black background which gives you room to play with the format of your slogan, maybe starting from left corner and shape the words a little to center, a way that corresponds with the universality of your message. Also I see that you maybe tried to make some shades in boarders of the picture which is a great idea but maybe having the while boarder by the lower side of picture serves you better that dark boarders.
Well done my friend, your design has a sense of relaxation in it which corresponds well.