Bring on the Noise
The digital era has simplified buying music as a gift. Delivery is instantaneous, you can often buy music on a song-by-song basis and best of all, you aren't burdened by that sense of embarrassment you'd get when you buy the music your dad likes at a physical store. No one needs to know!
But dad still needs something to play music on. There are several inexpensive digital music player options available. Or you can give dad an iPod touch, a device that's just shy of being a smartphone. There's a wide spectrum of devices with different features and price points.
One thing to keep in mind is the user interface. Some digital players are easy to work with -- they have an intuitive user interface and simple features. These make great gifts for dads who love music but aren't used to handling complex gadgets. You may also want to consider the type of computer your dad has -- some devices work well with PCs, but not with Macs -- or vice versa.
With a little research and some legwork, you can pick out a digital music player that best suits your dad's needs and habits. And you don't have to worry about someone you know spotting you with an album of Slim Whitman's greatest hits.