I have searched and asked others for the answer to this but have come up dry: what is the name or technique in music where musical notes approximate/imitate speech? Note that I am not talking about vocoders where speech is modulated by tones or notes, but rather the technique of arranging notes so they sound similar in pitch/length to spoken syllables. An example is the intro to "Hot Blooded" by Foreigner.
First I thought you meant something like this but it seems that's not the case...
I don't know if what you ask actually has a name or not. However, it seems that it could be a part of the more general idea that music and speech have much in common. In this case, if you would use long notes for short syllables and vice versa, or weak notes for strong syllables, low notes for words which would be naturally spoken in a higher pitch, and so on, the music would become incomprehensible or at least illogical.
So, in general, to make music and text go well together, you would at least get the proportions approximately similar, only breaking them when you know what you're doing. Music matching syllables exactly would then just be an extreme case of this. Perhaps the term rhetoric in music could get you further.
In the intro of the piece you mentioned the notes are just the first notes of the main melody, which again seems to be composed according to these principles.
"Musical notes that approximate/imitate speech..." could be categorized as musical onomatopoeia -- music which imitates sounds of the environment including speech.
However, based on your example of Hot Blooded, I think that you are instead looking to describe musical notes that outline a sung melody. If so, I think that the best term for this is simply lyrical melody.