BitterSweet Music is an Amazon Alexa skill that plays songs that enhance either the bitter or sweet tastes in the food that a user is eating. The user tells Alexa what he/she is eating and Alexa will identify the ingredients in the food, allow the user to choose one, and play a song that either complements the bitter taste of a bitter ingredient or complements the sweet taste of a sweet ingredient.

Multiple studies support tha claim that music and sounds can influence the way that something tastes. A prominent researcher on the subject, Oxford psychology professor Charles Spence, in his publiation entitled The Influence of Auditory Cues on the Perception of, and Responses to, Food and Drink claims that high-pitched music is often associated with sweet and sour tastes therefore listening to it while eating will enhance the sweet/sour tastes. Low-pitched notes correspond with bitter and umami tastes.

Other associations are made through other research, and these associations as they relate specifically to bitter and sweet sounds are combined below (these are what BitterSweet Sounds uses to choose songs to classify as sweet or bitter):

• Sweet: rich tones, upbeat, high-pitched, flute, piano
• Bitter: deep tones, low-pitched, sombre, brass

A popular application of this research is creating a sound experience in a resturaunt that will compliment the food and make it taste better.

In order to invoke the skill, the user should say "open BitterSweet Sounds"

To specify the food that the user wants to match music to, they can use the following utterances:

"{food}" "{food} please" "I am going to eat {food}" "I made {food}" "I cooked {food}" "I am eating {food}" "I ate {food}" "I cooked {food}" "I like {food}"

In response to the above utterances, Alexa will list the ingredients in the food and ask the user to choose one to enhance the taste of. The user needs to respond with one of the ingredients and then the ingredient will be matched to a song that will start playing. If the food is itself an ingredient (e.g. chicken), then no ingredients will be listed after the user specifies the food and the song will play immediately.

User: "Alexa, open BitterSweet Sounds"

Alexa: "Hi, welcome to the My Food to Music Alexa Skill. I will play music depending on food ingredients." "What food do you like or are you eating? You could say for example: I like salad or I'm eating salad"

User: "I am eating a hamburger"

Alexa: "Which of the following ingredients would you like to enhance with music? Cheese, beef, lettuce, ketchup, onion"

User: "cheese"

Alexa: plays a song that complements the bitter tastes in cheese

bittersweet.json defines the interaction model for the skill.

lambda_function.py is a serverless AWS labmda function that has all of the backend code. It takes a JSON file from the frontend of the Alexa skill based on the user's utterance, interprets the JSON file to formulate a generate a new JSON file representing the response that the skill should provide.

• allow the skill to recognize more food and corresponding ingredients, as well as the possible songs that the ingredients can be mapped to. This could potentially involve using a search API to find the ingredients in a given food or through consulting a knowledge base such as Wikidata. One method we considered for recognizing/classifying unknown/unclassified food is through using image recognition to identify the food.
• incorporate the other taste receptors (sour, salty, umami) and other factors that influence taste perception; for example, matching the texture of a food to a texture of sound will enhance textural components.
• lighting and color can also influence taste receptors, so using the light ring on the Echo or connecting it to lights in the home to enhance certain tastes by altering the lighting

There is potential for BitterSweet Sounds to be applied to health purposes such as increasing sweetness in food in order to satisfy someone's craving for sugar without him/her needing to eat a lot of sugar. It can also alter the taste of a food that a person doesn't like to make it taste better to them, which is useful in situations where a person needs to eat something they don't like the taste of. When someone is stressed, their tastes are distorted, which in most cases means a craving for unhealthy food high in sugar and fat, so BitterSweet Sounds can provide a way to distort the taste of foods in order to match the distortion that stress is causing. Additionally, enhancing the eating experience through changing taste perception could increase motivation by bringing more happiness into someone's life. Having happy experiences is associated with higher levels of serotonin, which is a neurotransmitter important in sleep and diet regulation, motivation, social behavior, and many other important human functions. Certain types of songs can increase conversation at the table; this idea combined with the happiness booster idea could also help foster better social interactions.