My MP4 has 4Gb storage, it has radio, video, photo and music functions. It has very long battery life for playing musics - I would guess that it can play 8 hours straight.
In addition to its tranquilizing effect, the MP4 also provides a window for me to my boys' world through their choice of music, exposes me to songs/musics I would otherwise not hear. Their choice of music was quite broad, from classical, contemporary classical, Jazz, Latin, Pop, R & B to Rock. I know a few names in classical music, Beethoven, Chopin, Dvorak ....which are all accounted for in their collection. I know little about pop music - which in fact forms a majority of their collection. I like many of them! The boys have good tastes.The music collection is a few years old now, I need an update in musics from the boys if they will help.
Looking around on a plane, I am definitely not the oldest any time, but my MP4 is definitely the most out of dated gadget every time. It can play long time, it can save battery on my iPhone, it works perfectly fine! No need to switch any time soon.