OnSong is designed to display the menubar above the content you are viewing. This allows the menubar to be hidden without shifting the visible content. However, if you are using content that has narrow or no margins, this may cause the menubar to hide valuable content.
To correct this issue, you can change your song viewer's behavior. To do this, go into the Utilities Menu by tapping on the gear icon in the Menubar. Choose Settings and then Display Settings > Song Viewer. Locate the Borders option in the Screen section and change the Top border to Thick. Then tap Done. This will push the content to be below the menubar when first viewed.