The Arabic word, Tarab, is special. Inseparable from a rich cultural lineage, the word has no English analogue, and a list of unwieldy nouns – ecstasy, trance, enchantment, rapture – is a pitiful evocation of its meaning: an emotional state triggered by performance of Islamic song. Steeped with aesthetic concepts alien to the western imagination, Indian classical music feels similarly remote, especially because access to an understanding of this esoteric art form is granted only through years of disciplined study in a fiercely pedagogical environment.

Impatient with the stifling teaching methods, my introduction to Carnatic Indian classical music through the violin was short-lived, but stumbling across old CDs rekindled a personal connection to music which I had long lost touch with. After tiring of archaic recordings on YouTube, my reunion with the genre culminated in a Sunday evening at the Barbican, attending the final night concert of the globally renowned Darbar festival, a 60-year-old annual festival of Indian classical music.

"The direction-dependent melody emphasises the context of each note, adding a layer of complexity absent in western music"

Indian classical music has its roots in ancient religious scripture, but the burgeoning of the Indian classical music canon occurred mainly during the 14th and 15th centuries and onwards. There are broadly two traditions: Carnatic and Hindustani, developed in southern and northern India respectively, although a plethora of regional styles arose from cross-pollination with local folk music. During the mid-20th century, a series of seminal encounters with western musicians led to a trend of incorporating Indian styles into popular music, but today, it’s rare for people in the West to give Indian classical music a studied listen other than perhaps a Ravi Shankar performance or two to bag a high grade in GCSE Music. This is reflected in audience demographics – at the Darbar festival the audience was as old and racially homogeneous as any at a performance of Beethoven’s 9th.

The first performer was Kushal Das (sitar), who began his recital with the Alap, an improvisatory invocation which introduced the raga – the scale/set of notes which acts as the scaffold for the piece. The ascending and descending arms of a raga might not be identical, and the direction-dependent melody emphasises the context of each note, adding a layer of complexity absent in western music. Similarly, ragas are temporally specific, crafted to be heard at certain times of day so that each raga’s melodic palette mingles with the ambience of the surroundings to heighten the emotional experience of both. The raga on this programme was a midnight one - 8:30pm in late October and celestially themed decorations were accepted as adequate approximations – and Kushal Das’s rendition of this weighty raga was inspired.

"The effect was of an unbroken swell of rhythmic vitality"

Visually imposing with a sound no less resplendent, the sitar is a plucked instrument, but less comparable to an acoustic guitar than to a bowed instrument in terms of tone control. Each note blossomed like a gong, festooned with overtones from the sympathetic strings and Kushal made abundant use of pitch bending, sliding notes by a semitone or more, lavishing ornamentation on the raga. Commandeering subtle shifts in character between subsections of the piece required great synchronicity between Sukhwinder Singh (tabla) and Kushal Das, especially with the complex syncopations of the gaat section, and the effect was of an unbroken swell of rhythmic vitality.

After the interval, the audience were introduced to the evening’s headline act: Kaushiki Chakraborty, a regular performer at Darbar and vocalist extraordinaire. Kaushiki is a leading exponent of the khayal form of performance (the word aptly has its root in the Persian word for imagination) which distinguishes itself by its virtuosity and prolific ornamentation. Kaushiki introduced the song with plain, languid tones, offering the raga to the audience in its purest and most innocent form, before peppering the notes with deft trills and scintillating multiple-octave runs. Improvising musical phrases and details is hard enough but spinning the very arc of the story from thin air had a curiously disarming effect. Listening to Kaushiki erecting an epic musical edifice in real-time necessitated the relinquishing of expectations, and I had no choice but to place my complete faith in the performers’ ability to guide the audience through an auditory construction so palatial that to wander in it alone would be disorientating.

The following two miniature pieces were sweet but felt like attempts to squeeze in as much music as possible before closing time at 10:30 pm, and this hurried ending was disappointing especially after the preceding behemoth compositions. Failure of planning hardly seems to be an apt criticism however - Indian classical music has such extraordinary depth and richness that it seems bound to overflow any structural inhibitions placed upon its communication. Indeed, all-night concerts in India are commonplace.

Adrift on cold London streets at 10:45pm, I was feeling the sting of withdrawal and a lingering elation. Exhausted from the performers’ generous apportioning of emotion, I felt as if I had participated in, and not just listened to, the evening’s music making – a testament to the communicative power of the musicians. Indian classical music had embraced me whole-heartedly, and my passion for the genre was cemented. Everything from the temporal specificity of its melodies to its meandering improvisations seems to eschew portability: the hypnotic rhythms and immersive auditory landscapes that the performers painted did not seem amenable for listening during a morning commute on the London Underground. Indian classical music is an all-consuming form of art that inspires complete abandon, and dedicating a mammoth five hours to that experience – especially in an era of waning attention spans – is a necessary retreat and a dizzying joy.