His head shawled in a tallit, the prayer leader intones the blessing for Hallel, the collection of psalms to mark the New Moon, as he gently strums on a guitar. Some of the minyan are already swaying while beside him a man waits to tap out a beat on a goblet drum.

Music has long been a feature of Progressive synagogues in this country but this is happening at Ner Israel, an independent Orthodox congregation in Hendon. The man with the guitar is Rabbi Yaakov Klein, who arrived in the UK just over a year and a half ago to inject some of the spirit of early Chasidism into the staid routines of British Jewry.

A monthly musical Hallel on a weekday — for the New Moon, at Chanukah or in the intermediate days of a festival — is one of the innovations of Eilecha, part of the Jewish Futures family of enterprises that include the outreach organisation Aish and the social action charity Gift. Its name means “to you”, which expresses its fundamental aim of deepening the connection with God “not as a thing to be reacted to but as Being to be related to”, he says. It’s a word “that connotes relationship — like the I-Thou of Buber”.

Early Chasidism emphasised the joy of worship and of encounter with the Divine presence, and he hopes to inspire “a return to the original ideals, energy, vision and experience” of Chasidut. While it offered a different path to religious fulfilment than the intellectual elitism of study, it nevertheless also encouraged a change in consciousness: and though only 29, he is already the author of three books on Chasidic thought.

He runs sessions in schools, synagogues and other centres, using music, stories and sharing ideas, which for him are not concerts but “a genuine form of worship, of devotion”. In one of his regular tips to Manchester, he recently did seven events in a day ranging from frummer schools like Etz Chaim or Beis Yaakov to the broader-based King David.

His own work he sees as part of a wider movement within the Orthodox world that puts a premium on spiritual experience. People may see the details of practice, the what to and when to do, but not always “the why, which is the soulful premise and energy and motivating factor, which is sometimes lost due to our intense focus on the structures we have created to protect and preserve it”.

Coming to the UK was “the furthest thing from my mind” when the Israeli-based New Yorker was approached by Jewish Futures head Rabbi Naftali Schiff to try something here. There is not a major Orthodox community in the USA he can think of where this kind of activity is not going on, led by mashpi’im — spiritual mentors or religious influencers. “This is happening everywhere and it’s exploding.”

The youngest of eight children in a central Orthodox home with a rabbinical father, he studied at yeshivot in the USA and Israel. But from an early age, he felt something was missing and in his teens experienced “a period of feeling pretty disenfranchised by what I sensed wasn’t relating to that part of me that was looking for God — for a lived experience of faith instead of a conceptual a theological, academic sort of engagement.”

It was when he went to a small yeshivah in Jerusalem that was intended for those, like himself, who were “finding their way” that he met someone who introduced him to a more soulful experience of Judaism and the ideas of the Chasidic pioneers.

That “changed everything for me. I said, ‘Wow I can upgrade my definitions of the God I was having a hard time believing in because it wasn’t so believable. I can expand my definition of Shabbat so that it doesn’t have to be something I consider restrictive but I can upgrade my perspectives on what this day is, what the invitation to an immersive spiritual experience is’.”

It led to an understanding of Creation as an emanation of the Divine and of the physical world not as “hiding God but as potentially revealing God” and of spirituality as not confined to the study hall but something “potentially experienced… in every moment”.

He was so inspired that he wrote his first book, Sparks from Berditchov, about the teachings of the early Chasidic master, Rabbi Levi Yitzchok of Berditchov, at the age of 18 which was published a few years later in 2017. His next work, Sunlight of Redemption, explored the ideas of Rabbi Nachman of Breslov and his third, The Story of Our Lives, was inspired by Rabbi Nachman’s tale of The Lost Princess. He came to realise “this short story contained within it all of the multifarous elements of the theological and philosophical revolution that I had experienced in my mind couched within brilliant symbolism”.

It is about a king who loses his daughter and his viceroy’s mission to find her. The experience of search, he says, “is itself finding in some way”.

He launched an online vehicle, The Lost Princess Initiative , which attracted a growing following as the Jewish world went intro lockdown, ranging from contemporary Chasidism to people who had never kept Shabbat in their lives. He gathered other like-minded mashpi’im as tutors including Rabbi Moshe Weinberger, who was a longstanding friend of his father and who pointed Rabbi Schiff in his direction.

“There is a desperate thirst across the spectrum for meaning, for the why,” Rabbi Klein says. “We need a sense of purpose, people need to fit into eternity. They want more than the temporal experience of materialism that is more accessible than ever.”

Five hundred years ago, “maybe there was the illusion if we could just have financial security that would be enough”, he says. But now people recognise it is not.

His schedule includes weekly classes for men and women and one to ones, sometimes involving a walk round the park; he puts out social media content and has recorded a 10-part series of short video talks as an introduction to Chasidic thinking for Aish’s Maven series.

The Ba’al Shem Tov brought music back to the forefront of Jewish life, he says. “You can sing with your eyes closed and your mind aflame with the deepest, deepest ideas about what it is we are singing and that becomes a way to let God into your life.”

Eilecha videos are available on Youtube