Here are the latest Back Bay - Midtown neighborhood notes:

Idyllic serenades

The Chamber Orchestra of Boston will present “Idyllic Serenades” at 7:30 p.m. on Saturday, May 11 at the First Church in Boston, 66 Marlborough St.

The orchestra will perform the world premiere of “Concerto for Horn and Strings” by Robert Edward Smith with soloist Kevin Owen. Also featured will be serenades by Janacek, Volkmann and Balmages.

A complimentary reception will follow the performance.

Tickets range from $25 to $50, with student tickets at $15.

For tickets and more information, visit www.chamberorchestraofboston.org or call 617-266-1626.

Old South is 350

Old South Church will celebrate its 350th anniversary with a family-friendly party from12:30 to 2:30 p.m. on Sunday, May 12 at the church, 645 Boylston St.

A special festival worship service will be held at 11 a.m. Following the service, the community will gather outside with herald trumpets, guest speakers and an interfaith blessing. At 1 p.m. the party will start, with food, games, musical entertainment, crafts and fun for all ages.

Admission is free.

Further information can be found online at www.oldsouth.org/350th-anniversary or by calling 617-536-1970.

Authors at the library

Authors John Urschel and Louisa Thomas will be the guest speakers from 6:30 to 8 p.m. on Tuesday, May 14 at the Boston Public Library, 700 Boylston St.

Urschel and Thomas will discuss their book “Mind and Matter: A Life in Math and Football.” For Urschel, what began as an appetite for puzzles as a child quickly evolved into mastery of the elegant systems and rules of mathematics. But when he joined his high school football team, a new interest began to eclipse the thrill he once felt in the classroom.

Accepting a scholarship to play football at Penn State, he refused to sacrifice one passion for another, and simultaneously pursued his bachelor’s and then master’s degrees in mathematics. He found a way to manage his double life as a scholar and an athlete, so when he was drafted to the Baltimore Ravens, he enrolled in his PhD at MIT.

One hundred seats are ticketed and each ticket comes with a copy of “Mind and Matter” that Urschel will sign. To secure a ticketed seat, visit www.eventbrite.com/e/mind-and-matter-book-launch-with-john-urschel-and-louisa-thomas-tickets-59124895153. Books can be picked up before or after the talk. Additional books will be available for purchase at the event.

Call 617-536-5400 for further details.

Mansion tour

A public one-hour tour of the Ayer Mansion, 395 Commonwealth Ave., which showcases the striking interior and exterior embellishments designed and created by Louis Comfort Tiffany, will be offered at noon on Wednesday, May 15.

Reservations are required. Admission is $15 general and $10 for students and seniors.

To make a reservation, send an email to ayermansion@gmail.com or call 617-536-2586.

Indian Americans in Massachusetts

The Boston Public Library, 700 Boylston St., will present “Indian Americans in Massachusetts” with author Meenal Atul Pandya from 6 to 7:30 p.m. on Wednesday, May 15.

Indians are the most recent immigrants in Massachusetts and though they are a small minority, their contributions are numerous and far-reaching.

Pandya will highlight the influence of Indians on Massachusetts history, such as Swami Vivekananda who arrived in Boston in 1893 and left a legacy of Hindu philosophy; Sushil Tuli, who opened the Leader Bank, as the first and only minority-owned bank in the state; and the Deshpande Center for Technological Innovation at MIT, created with the grant of $20 million by Desh and Jaishree Deshpande, that empowers MIT’s researchers to develop innovative technologies.

Admission is free. Call 617-536-5400 for more information.

Classical trio

Trio Gaia of the New England Conservatory of Music will perform in a free concert from 2 to 3 p.m. on Thursday, May 16 at the Boston Public Library, 700 Boylston St.

The trio of Grant Houston, violin; Yi-Mei Templeman, cello and Andrew Barnwell, piano, will perform classical favorites.

For more information, call 617-536-5400.

Walking tour

A special walking tour of the Katharine Gibbs School and Gibbs College will be held from 10 a.m. to 12:30 p.m. on Saturday, May 18 as part of the Boston Preservation Month activities. Participants will meet outside the Boston Public Library, Dartmouth Street entrance.

The Gibbs School was the most famous school of its kind from 1911 to 2011. Katharine Gibbs made sure all the campuses from Boston to Providence to New York were in beautiful buildings in elegant parts of their cities, and what could be more elegant than the Back Bay in spring.

A former Gibbs dean will conduct the tour of the Gibbs sites in the Back Bay. Admission is free.

Send an email to roseadoherty@aol.com or call 781-449-3175 to register and for more details.

Two to tango

Emmanuel Music will present “Tango!” with two performances at 8 and 10 p.m. on Saturday, May 18 at Emmanuel Church, 15 Newbury St.

The program will explore the various stylistic connections that connect the classical and jazz idioms in the dance music of the tango as it has evolved through the ages. The Arneis Quartet will collaborate with Julien Labro, whose musical roots lie in the improvisatory nature of folk and jazz music. They will play selections by Astor Piazzolla, Heitor Villa-Lobos, Luis Enriquez Bacalov and Labro.

Tickets are $30 general admission and $10 for students.

For more information, call 617-536-3356 or visit www.emmanuelmusic.org.

Bach cantatas

Emmanuel Church, 15 Newbury St., is presenting its 42nd season of the J. S. Bach Cantatas at 10 a.m. on Sundays now through May 20.

The orchestra and chorus of Emmanuel Music will present weekly performances of the cantatas and motets of J.S. Bach and others, conducted by Ryan Turner.

For more information, call 617-536-3356 or visit www.emmanuelmusic.org.

Collections tour

The Massachusetts Historical Society, 1154 Boylston St., will host tours of the collections of the society at 10 a.m. on Saturdays.

Led by an MHS staff member or docent, the 90-minute tour focuses on the history and collections of the MHS.

The tour is free and open to the public. Reservations are not required for individuals or small groups. Parties of eight or more should contact the MHS.

Further information can be found at www.masshist.org or by calling 617-646-0560.

Library tours

Boston Public Library volunteers will give art and architecture tours of the McKim Building, a National Historic Landmark, in its main building, constructed in 1895, throughout the week.

Highlights include the murals of John Singer Sargent, Pierre Puvis de Chavannes and Edwin Austin Abbey and the work of architect Charles Follen McKim.

Self-guided tours are available as well, and literature describing the architectural highlights is available on the web at www.bpl.org/central/tours.htm.

For tours by appointment, call 617-536-5400.