2 days after ordering my Grace Message Player, it came from Amazon in perfect condition (I got prime yo!). I plugged the power cord in, and plugged the male thingy into the Grace thingy, and bam, we have had on hold music ever since. After a few minutes of music, they have a male voice come on explaining that we care but we are busy...we have not forgotten you etc etc, and then some more music, and then a female voice saying basically the same thing. I guess I could load an mp3 with some sales stuff on it, but I kind of like the neutural message that they already had on the machine. I am sooo glad I got this thing. Highly recommended. If you don't like it or it does not work, I bet Amazon would take it back, too.
If it is a genre, hold music, it's fair to say, is a troubled one with few hits. It's not really meant to be loved or even listened to — it's meant to communicate something specific: Don't hang up. (Cornell makes this plea specifically at the end of his song.) Silence is believed to be a death knell for phone calls — people will simply think the line is dead and hang up. This is true even on non-hold calls; it's why phone companies transmit something called a "comfort tone" over phone lines, a barely audible synthetic noise that signals a connection is still there.

2. If the hold is more that a couple of minutes make sure to thank customers for their time. Apologize for delays if hold time is significant.
On average, 5 to 15 seconds of music plays between each message blurb. Keep your audience in mind: musical breaks that are too long are boring, but message blurbs that are long or too detailed can be overwhelming. In most cases, 5 to 15 seconds, between message blurbs that don’t exceed 30 seconds are usually appropriate.