As you walk, you will jostle the baby around and gravity may bring the baby down into position in the birth canal.
What this means is that there are no moving parts, and as a result, the tunes will not "skip" in the way that a CD player would if you happen to jostle it.
Solar systems do not jostle each other in space.
In addition, you will want to pack your patience, especially if you are shooting in a large crowd with other camera-wielding spectators who may jostle you while they try to snap their perfect fireworks photo.
Old & new buildings jostle for space near the bus station.