Taj Mahal is an ambassador of Shah Jahan's strong interest in building and artistic innovations. The new architectural style includes aspects that were to impinge much of subsequent Indian architecture. Symmetry along two sides of a central axis, new columnar styles, curvilinear forms, and symbolic decorations based on naturalistic plant motifs are all characteristics of the Shahjahan style that can be found in the Taj Mahal Complex.
The mausoleum is entirely clad in white marble. Alluding to the stone's luminosity, the Mughal poets compared it to early dawn or to a cloud. Kalim wrote:
It is a [piece of] heaven of the colour of dawn's bright face, because from top to bottom and inside out it is of marble - Nay, not marble because of its translucent colour (av-u-rang) The eye can mistake it for a cloud.
Kanbo refers to “the illurruned tomb (rauza-i-munauwara) on who’s every stone slab from early morning until late evening the whiteness of the true dawn is reflected, causing the viewer to forget his desire to move towards the highest heaven”.
Under the reign of Shah Jahan the symbolic content of Mughal architecture reached its peak. Inspired by a verse by Bibadal Khan, the imperial goldsmith and poet, and in common with most Mughal funerial architecture, the Taj Mahal complex was conceived as a replica on earth of the house of Mumtaz in paradise.
This theme permeates the entire complex and informs the design and appearance of all its elements. A number of secondary principles were also used, of which hiearachy is the mostdominant. A deliberate interplay was established between the building's elements, its surface decoration, materials, geometric planning and its acoustics. This interplay extends from what can be seen with the senses, into religious, intellectual, mathematical and poetic ideas.
In the Taj Mahal, the hierarchical use of red sandstone and white marble contributes manifold symbollic significance. The Mughals were elaborating on a concept which traced its roots to earlier Hindu practices, set out in the Vishnudharmottara Purana, which recommended white stone for buildings for the Brahmins (priestly caste) and red stone for members of the Kshatriyas (warrior caste). By building structures that employed such colour coding, the Mughals identified themselves with the two leading classes of Indian social structure and thus defined themselves as rulers in Indian terms. Red sandstone also had significance in the Persian origins of the Mughal Empire, where red was the exclusive colour of imperial tents.
Its symbolism is multifaceted, on the one hand evoking a more perfect, stylised and permanent garden of paradise than could be found growing in the earthly garden; on the other, an instrument of propaganda for Jahan's chroniclers who portrayed him as an 'erect cypress of the garden of the caliphate' and frequently used plant metaphors to praise his good governance, person, family and court. Plant metaphors also find a commonality with Hindu traditions where such symbols as the 'vase of plenty' (purna-ghata) can be found and were borrowed by the Mughal architects.
Sound was also used to express ideas of paradise. The interior of the mausoleum has a reverberation time (the time taken from when a noise is made until all of its echoes have died away) of 28 seconds providing an atmosphere where the words of the Hafiz, as they prayed for the soul of Mumtaz, would linger in the air.
The building was also used to assert Jahani propaganda concerning the 'perfection' of the Mughal leadership. Wayne Begley put forward an interpretation in 1979 that exploits the Islamic idea that the 'Garden of paradise' is also the location of the 'throne of god' on the day of judgement. In his reading the Taj Mahal is seen as a monument where Shah Jahan has appropriated the authority of the 'throne of god' symbolism for the glorification of his own reign. Koch disagrees, finding this an overly elaborate explanation and pointing out that the 'Throne' sura from the Qu'ran (sura2 verse 255) is missing from the calligraphic inscriptions.
This period of Mughal architecture best exemplifies the maturity of a style that had synthesised Islamic architecture with its indigenous counterparts. By the time the Mughals built the Taj, though proud of their Persian and Timurid roots, they had come to see themselves as Indian. Copplestone writes "Although it is certainly a native Indian production, its architectural success rests on its fundamentally Persian sense of intelligible and undisturbed proportions, applied to clean, and uncomplicated surfaces."
Uniformity of shapes has been set in a particular hierarchical accent. One type of column, called the Shahjahani column is used in the entire complex. It has a multi-faceted shaft, a capital builtup from miniature arches, concave elements and a base with four multi-cusped arched panels.Proportions and details of the columns vary according to their position in the complex; simplest in the bazaar streets, larger and richer in the funerary area.
The chief building of the entire complex is the mausoleum and the most naturalistic decoration appears here. The flanking buildings; the mosque and mihman khana [Guest House meant only for assembling for prayers] share mirror symmetry and display less naturalistic and less refined ornament; in the garden buildings, it is used only sparingly; and none appears in the Jilaukhana or the bazaar and caravanserai complex. The elements of the subsidiary units are arranged with the same mirror symmetry. Integrated into the overall qarina symmetry is centrally planned elements; the four-part garden, the four-part bazaar and caravanserai complex, and the miniature chahar baghs of the inner subsidiary tombs. The mausoleum and the great gate have centralized plans. Each element plays an indispensable part in the whole, if even one of the parts was missing; the balance of the entire composition would be destroyed.