Now it looks a little funny, no need to make the 5 bold either. Keep it all the same font, and make the sound waves the same height as the "m", centered a little more so it's coming out of the O shape in the 5 instead of the top. Just a little more kerning (and tracking) too, your spacing is a little out, and needs some fixing.
Font's of choice: Helvetica (for anything plain), Futura (for anything fancy), Myriad (in the middle). You cannot go wrong using a combination of the many styles availible for these three fonts. Times in CAPS also looks real fancy if you make the first letter of each word a few point sizes bigger.
As far as typography goes, it is always best to underdo it. Overdone typography looks awful. A good rule is to get it the way you want it, then go back a few steps. It's really subconcious that way. At colledge, the greatest skills I learnt were from a teacher who had a passion, hmm maybe an obsession for typography. It really washed out onto me (and the rest of the class) too. I couldn't be more greatful for those skills she taught us. In this day an age of anybody (any kid) with a computer can be a graphic designer, good, true typography is so often overlooked. Yet when you see it, you know what it is and how good it looks.
By the way what do you do mash, are you are pro graphic designer? Or a hobby dude?
I'm a web designer, just starting off in my career, with a colledge education and a bit of freelance work behind me. Man it's tough, the jobs are out there, but you gotta work hard to get them. I've applied for many, and so far not a single reply. Kinda dis-heartening. Lucky I have confidence in my work.