Hahn has played with orchestras such as the London Symphony Orchestra, New York Philharmonic, Singapore Symphony Orchestra, just to name a few.

The choir began approaching and performing with other orchestras such as the Royal Philharmonic Orchestra, The London Symphony Orchestra and the Philharmonia Orchestra.

Lorna has performed in many orchestras, such as the London Symphony Orchestra, Academy of St. Martin in the Fields, and Pittsburgh Symphony.

He was first horn with the English Chamber Orchestra from 1972 to 1986, and has also been a member of other noted orchestras such as the London Symphony Orchestra.

The choir and its members have appeared regularly in major London concert halls working with orchestras such as the London Philharmonic Orchestra, and sing onstage at the English National Opera.

He was guest conductor for a number of other orchestras, such as the Berlin Philharmonic, the London Symphony Orchestra, and the New York Philharmonic.

From the outset professional orchestras such as the London Symphony Orchestra, the Royal Philharmonic Orchestra, the Boyd Neel Orchestra and several others were engaged.

During his early years he began traveling frequently to Europe to perform and record with orchestras such as the London Symphony Orchestra and Berlin Symphony Orchestra.

He has given solo performances with major orchestras such as the London Philharmonic Orchestra and Royal Philharmonic Orchestra.

His activities also included conducting orchestras such as the London Symphony Orchestra, the Concerts Colonne, and others in Copenhagen, The Hague, Madrid, Athens and Prague.