Many would say it’s rash to talk of a Vietnamese culture because the country actually does not have a distinguished one. But personally I think we do have our own culture, only that it is not characterized by enough distinct features as are other long-standing ones like Chinese, Indian, Arabian, or European cultures. The cultural difference can be found, for example, in language and music.
In music alone, I dare say with all my poor knowledge and considerable humility that there are profoundly Vietnamese sounds. A friend of mine, a guitarist who lived most of his golden day in Saigon before 1975, once performed an arpeggio on his guitar. “I’ve played the style of Japan,” said he, “Now do you want me to play the same arpeggio in a Vietnamese way?” He then played it on the six strings of the guitar, and the instrument gave an arpeggio which was undeniably that of Vietnam. He went on playing it in a Chinese and an American style, and I saw that there was actually a distinct difference between them all, although he was playing the same arpeggio. So, put aside all nice words on his talent and I must admit that Vietnamese music has its unmixed identity.
A songwriter who deserves much credit for Vietnamese-styled music is, in my opinion, Pham Duy. Many of his songs (or, more exactly, all the songs by Phạm Duy that I’ve heard so far, and they are not many in number) are truly imbued with a Vietnamese spirit.
Sông này đây, chảy một dòng thôi,
Mây đầu sông thẫm tóc người cuối sông. [1]
In terms of language, it is likely that national language is the mirror that reflects a people’s culture, which is why a translation is forever a translation in itself if its targeted readers do not share the culture from which the original arises. There is a wide and colourful vocabulary that belongs only to a country under communist influence like Vietnam, whose meaning no foreigners can grasp. “Báo cáo”, “nghị quyết”, “văn kiện”, “quán triệt”… are just part of a whole big dictionary. I challenge any best translator to convey their full meaning, with tone as an integral part, to an English speaking audience. Impossible to translate, isn’t it? They are not just nouns or verbs; they have become adjectives, too.
Also there are words and melodies that can conjure up in our mind different moments and times of a whole country. People living in Vietnam in the times of the planned, centralized command economy, or the times of economic subsidization for short, may find so many distant memories of their old springs awaken everytime they hear Here Comes Spring [2], or A Quiet Spring [3] on air before Tet holiday.
May I call those songs “lasting reminders of the past Vietnam”? May I hope that there will be pieces of music that are reminders of the present Vietnam, the Vietnam that we are now living in? And you, I feel sure that you each hold in your heart songs that may take you back in time, too. When people in a country share the same memories of hard times they have gone through, we will see a culture. People who lived in pre-1975 Saigon shared memories of their life then, by that a culture was formed and we've got no excuse to exclude it from Vietnamese culture. A part of our national culture, it marked its existence with splendid works in such art forms as music and poetry. Art is guiltless; besides, many would agree that those were real masterpieces that could touch millions of hearts.
Yes, when people share the same visions of the past, we will see the making of a culture. And when they share the same future plans, we will see a nation-state, though not necessarily in a political sense.
Foolish generalization, isn’t it? Well, that’s enough. Rarely do I philosophize. 
[1] Golden Flower Hill (Đưa em tìm động hoa vàng), music by Phạm Duy, lyrics by Phạm Thiên Thư
[2] Em ơi mùa xuân đến rồi đó
[3] Mùa xuân nho nhỏ