As a music teacher in schools, I seldom had a piano never mind a pianist to play it. I am NOT as pianist. I can thump out chords and simple accompaniment but not while my choir or class is singing. Because I taught a few years ago before digital recordings were common, I didn't have simple or small devises to carry around and use. Even when I had a "music room" my equipment was basic and so using recorded singing accompaniment was very seldom part of the singing.
When we did musicals with young children or young adults, there were usually recorded accompaniments available and I avoided them at all costs. Let's see how your ideas compare to mine.
1. The Good - All of us have sung along with the radio. If you are old enough and watched American television you even "Sang Along with Mitch". Mitch Miller made the sing-a-long popular by having the words to the songs his band was playing show on the bottom of the screen. Check out the video on Thoughtful Thursday and see.
However, I really think that after you have learned a song or sung it for fun, you need to get away from the restrictions of a recorded accompaniment.
2. The Bad - I found that recorded music is SO unforgiving that I, never mind the children, get frustrated trying to sing with it. Worst of all, if you get off the beat, it is almost impossible to get back on. With a packaged accompaniment, it is well nigh impossible to be creative. Doing a rubato or even a ritard where YOU and the singers feel it, is just not going to happen. When someone drops the ball and misses an entrance, too bad so sad, the music moves on without you. That inflexibility is just not what singers use well.
3. The Ugly - If we have a song with some tricky parts, our amazing Kristy will pull out key notes especially as we are learning, so that the parts in question can find their entrances. Oh that isn't going to happen with a recording.
When a rhythms get out of sync, the recording keeps going and only emphasizes
how bad it really is. Your accompanist can thump out the right rhythm and you can get back on track.
If the singers are not in tune, the music carries on and there is little chance that they can find that RIGHT note. the flexibility of a Capella or accompanied singing is so much more helpful. Of course, the "live" accompaniment has to be on the same page as the singers. When I went to an Il Divo concert, the conductor of the orchestra thought he was the act. He forgot to pay attention to the singers. They even looked over at him a number of times but it didn't help. Maybe that time, a recording would have been better.
I know sometimes it recorded accompaniment may seem like THE answer. I urge you to go without accompaniment or have an accompanist wherever possible. Singing can be very stilted and non-creative otherwise. What do you do?