I will be the first to admit that I haven't paid much attention to SMART Technology products since the iPad was released in 2010. I was a certified SMART Trainer, as my current high school has a SMART Board at every teaching station. But there are subjects where a SMART Board just doesn't make sense in the iPad era–and secondary music (other than, perhaps Theory) is one of them.
SMART Boards can work well in the elementary classroom, however. In many schools, elementary music during the day is taught as general music, in rooms with flexible (or no) seating where a teacher interacts with their students to teach general concepts in music. These teachers lay the foundation for secondary music educator, and their work is priceless.
A number of my elementary colleagues use SMART Notebook to create interactive presentations that allow students (generally one at a time) to draw on the board, reveal items, arrange items, or to use SMART Notebook's ability to embed sounds in the Notebook file and to make an item play a sound when touched from that embedded sound.
There are iPad apps that will allow students to draw on the iPad, reveal items, or arrange items. But linking audio sounds to an object is a missing feature–tied to iOS's locking of the music player app. You can access audio from nearly any app, but you cannot write to that audio collection from the iPad (you have to use a computer and iTunes). You cannot link an audio file in Keynote, nor can you do so in Explain Everything.
However, the latest version of SMART Notebook allows you to create a SMART Notebook file on a computer, to embed and link audio, and then to import that finished file to your iPad in SMART Notebook for the iPad, where the embedded audio file should work (I have found a couple of instances where this did not occur).
It is only a matter of time until Apple solves the problem of writing to the iPad music library, and I'd be surprised if the next version of iWork for the iPad (Pages, Keynote, and Numbers) did not offer more functionality, such as attaching audio to objects in Keynote.
Still…if you are a SMART Notebook user, and you have resisted the iPad because you could not link sounds, you now have a solution to that problem.