In general, each photo will have a 7 second screen time (including transition time between photos). So, that would equal about 8-9 photos per minute. If an average song lasts 3 minutes, you would need about 24-27 photos per song. This will also allow for an intro and conclusion if you so wish. Keep in mind, more basic transitions and photo effects will run slightly faster than the more complex ones. We will determine the style of slideshow you prefer by asking you some simple questions after you place your order.  In general, we don’t recommend making a slideshow with more than 200 photos as it can be very lengthy to view as well as to create.