In GNOME Music (version 3.12.2) there is a little issue in the selection mode. As long as an entry is unchecked, the checkbox hides the frame border of the entry. When activating a checkbox, its background gets (kind of) transparent and reveals the entry's frame border. In addition to this, the buttons in the bottom action bar change their size when selecting/unselecting an entry.
In GNOME Music (version 3.12.2) there is a little issue in the selection mode. As long as an entry is unchecked, the checkbox hides the frame border of the entry. When activating a checkbox, its background gets (kind of) transparent and reveals the entry's frame border. In addition to this, the buttons in the bottom action bar change their size when selecting/unselecting an entry.
Unchecked:![selection-1](https://cloud.githubusercontent.com/assets/6241153/4188728/ac9cb974-3775-11e4-8561-438534086443.png)
Checked:![selection-2](https://cloud.githubusercontent.com/assets/6241153/4188732/b8645ea6-3775-11e4-9a31-9d9b039196b1.png)