For over 30 years, I have been working in the art and culture community in Hong Kong, participating in the operation of the Hong Kong Arts Centre, serving as the Chief Executive Officer of the Hong Kong Arts Development Council, undertaking planning work for the West Kowloon Cultural District, and also serving as the Dean of the Hong Kong Academy of Arts. Over the past 30 years, I have witnessed Hong Kong gradually becoming a cultural city characterized by entertainment, art, and creativity. How can a city become culturally rich? In a broad sense, culture can encompass many different elements of life. Urban culture can be composed of four elements, namely beliefs and values, daily lifestyle, art and creativity, and memory and tradition. Beliefs and values refer to what urban people perceive as right or wrong. Geography, race, religion, and education all affect their beliefs and values. Daily living style refers to how urban people meet their basic needs. People's food, clothing, housing, language, entertainment, and sports all constitute the lifestyle of this city. Art and creativity refer to the creative culture of a city, including artistic atmosphere and cultural industries. Memory and tradition refer to the historical context of a city. These four elements contain various meanings of culture. Different cities correspond to different regions, economies, social environments, population structures, and historical contexts, thus nurturing and developing different cultural connotations and appearances. The existence of cities in human civilization is long-term and stable, and cities with a history of over a thousand years and still active can be said to be abundant. And urban culture has slowly developed and changed throughout its long history, to this day. I call this cultural concept the "cultural spectrum". The Guangdong Hong Kong Macao Greater Bay Area consists of nine cities in Guangdong Province, along with Hong Kong and Macau. Although this is a regional development concept driven by the state, this region has existed since ancient times. Guangzhou, as a city, has a history of over two thousand years. Through multiple dynastic changes, wars, development, and construction, this place has nurtured the famous Lingnan culture and become an important component of Chinese culture. When it comes to the Cultural Bay Area, if we use the concept of "cultural spectrum" to look at the 11 cities in the Guangdong Hong Kong Macao Greater Bay Area, we will see a rich cultural scene. 11 cities, each with its own district and streets, each with its own unique culture. Every city has its own suburbs, every village has its own culture. We can take a closer look at how each city constructs its own beliefs and values, daily lifestyle, art and creativity, memory and tradition. Each city has both differences and commonalities. We can analyze the cultural interaction between each city and collect cultural and economic data, as well as the distribution of cultural institutions and talents in the entire Bay Area. How can the Greater Bay Area cultivate high-quality cultural consumption? How to preserve historical buildings? How to inherit intangible cultural heritage? How to establish a new era of Bay Area culture? From the perspective of "cultural spectrum", I propose three words to establish urban culture, namely mixing, fermentation, and accumulation. Mixing, fermenting, and accumulating the four elements of the "cultural spectrum" from the 11 cities in the Guangdong Hong Kong Macao Greater Bay Area on different platforms and in different combinations can produce different cultural products. For example, the martial arts tradition in Foshan, combined with Hong Kong's film art, gave rise to the Ye Man film series; The lion dance tradition in Guangdong, combined with animation technology, gave rise to the male lion youth animation, which was then adapted into a musical through the Guangzhou Grand Theatre. The 11 cities have always been in the same region, with interconnected cultures and stories, such as the story of Huang Feihong, the story of Guangdong herbal tea, and the story of the Anti Japanese War. I often use a metaphor: culture is a pot of soup, and a city's culture is a pot of soup that has been rolling for decades, even hundreds of years. Lingnan culture and Bay Area culture are also a pot of soup with different ingredients inside. As long as it is well utilized, the temperature is raised, mixed, fermented, and accumulated. With the joint efforts of 11 cities, the culture of the Bay Area can quickly become a wonderful and hot "broth". Author: Ru Guolie (former Dean of the Hong Kong Academy of Arts)