Well there are many different capacitor chemistries and physical constructs to suit different use cases. They are quite diverse components..
For signal path audio the following dielectrics are often preferred
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Polypropylene (MKP / PP): Widely considered the gold standard for crossovers and audio coupling. They offer ultra-low loss, neutral frequency response, and high linearity. (low distortion)
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Polystyrene & Teflon (PTFE): Exceptional precision and minimal signal colouration, frequently used in sensitive low-level equalization and boutique audio circuits.
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Polyester (MKT / PET): A budget-friendly alternative with higher losses than polypropylene, sometimes preferred to smooth out high-frequency harshness.
With regard to construction types - again there variation depending on use cases some better for signal path audio than others.
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Film and Foil: Constructed with separate layers of plastic film and actual metal foil (like tin or aluminum). They offer superior current handling and are generally regarded as the best-sounding for signal coupling.
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Metallized Film: Built by evaporating a thin metal layer directly onto the film. They are compact and cost-effective, though slightly less dynamic than foil variants.
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Ceramic (C0G / NP0): Stable and linear enough for high-frequency RF bypassing or small-value filtering, but Class 2 ceramics should be strictly avoided in audio paths due to microphonics and nonlinearity ie adding distortion.