Humans like music that falls in our vocal range and tone and tempo similar to our heartbeats. To most animals including cats, human music falls into an unrecognized category. Their vocal ranges and heart rates differ from ours. They have the ability to appraise songs suitable to our ears. The heart rate of cats is higher than ours and therefore cats prefer music in the frequency range of cat vocalization. Animals can learn to recognise a sequence of notes to a different key so that the sequence uses the same relative notes but the key is different, they can't recognize the relationship between the notes any more. To that extent, we understand music in a different way to animals. Latest research suggests that music is beneficial for cats in a surgical environment and cats have shown a proclivity for classical music and become more calm, confident and tolerant throughout the clinical evaluation. This presents in lower values in terms of respiratory rate and pupil dilation. Heavy metal music when presented is stressful to cats.