GENERAL GUIDELINES FOR MUSIC CLEARANCE
In order to be as safe as possible from claims of copyright infringement, it is best to not request that the composer/music producer even listen to another given piece of copyrighted music, let alone be instructed to "come close" to the same. The ideal scenario is for "original" music to be truly original - to arise organically from the composer's emotional response to the film and/or voiceover. Realistically, however, playing an example of the type of music one wishes for a given campaign or project can be very helpful to those responsible for creating the music for your commercials, and a music producer can generally "cop a groove" via tempo and stylistic patterns - even common harmonic motion, without fear of infringement, PROVIDING that the original "source" rhythmic and/or melodic elements are NOT replicated. These would include not just note-for-note duplication for a given number of notes or measures of music, but also imitations that stimulate the hearer to "fill in the blanks" and aurally assume they are hearing a specific song or artist. While there is no set limitation to the number of consecutive notes that legally constitute copyright infringement in today's courts - (even the issue of "intent" does not cover the event that composers have been known to unconsciously adopt and recycle material and be found liable) a good rule-of-thumb is: if a co-worker down the hall thinks he/she is hearing Paul Simon, there's a strong likelihood that they are!
There are several components that go into "clearing" a song as "original" -
The greatest area of dissention invloves the issue of INTENT - which is why it's always preferable to "start from scratch" and not be unduly influenced by or told to copy anyone else's work. While titles are not copyrightable, lyrics most definitely are, including any recognizable turn of phrase or portion of an existing lyric. Even what appears to be the simplest of things can be essentially "judgement calls" by a musicologist or legal expert.
In addition to these factors, it is important to be careful that the ENTIRE work is original - legally a "tag" ending can be as much of an infringement as cloning throughout the piece.
Marilyn J. Harris