Decide on the type of theme song to make. The theme song sets the tone for the broadcast; it is important that the theme song and product it represents are congruent. For example, the theme song for a comedy should not be slow and depressing; it should be uplifting, fast and joyous. Determine the length of the theme song. This will give the composer some general guidelines when composing it.
Select an existing recording. Using an existing piece of music may be a lot easier than commissioning one to be made. Most popular music is copyrighted and protected, meaning the rights to use it will need to be acquired by the publisher. However, there are a number of sources that list music that is considered public domain, which can be used for free. Some sites that provide free music are: beatsuite.com, studiocutz.com and ibaudio.com.
Compose the music. Think of a basic tune or lyrics. Brainstorm this process and play with a few different ideas. Download music composition software like Sibelius, Reason or Cakewalk. These programs allow a user to compose their own music and offer a full range of instruments and tools. They can be a little tricky to learn at first. The type of theme song and genre of the show can help in determining what instruments will be used. For example many comedy shows such as Curb Your Enthusiasm, The Simpsons and Cartoons (such as Bugs Bunny) use light full or part classical orchestral instruments, brass, strings, percussion. The idea is that the instruments chosen deliver a sound that emphasizes the theme of the show. A Sci-Fi show may chose to use all synthesized electronic instruments to create a surreal, dream like melody. Theme music does not need to be complicated and the most important element to keep in mind is matching the rhythm of the music to the pace of the show. Lyrics can also be incorporated, if you choose. Lyrics are usually included to give the audience a back story about the show if they are tuning in for the first time. For example, The Fresh Prince of Bel-Air and The Brady Bunch both made use of these types of lyrics.
Hire a composer, band or orchestra. The composer can be instrumental in translating an idea for a theme song into a detailed composition. The fees for hiring a composer vary depending on their level experience and availability. Many individual composers have a network of colleagues (who are also musicians, and connected to bands or orchestras) that they may draw upon to complete the theme song.