VOTING AGREEMENT

     In  consideration  of  RCN   Corporation,   a  Delaware   corporation  (the
"Company"),  LME  Acquisition  Corporation,  a  New  York  corporation  ("Merger
Subsidiary")  and  Lancit  Media  Entertainment,  Ltd.,  a New York  corporation
("Lancit")  entering  into on the date  hereof an  Agreement  and Plan of Merger
dated as of the date hereof (the "Merger Agreement") which provides, among other
things,  that Merger  Subsidiary,  upon the terms and subject to the  conditions
thereof, will be merged with and into Lancit (the "Merger") and each outstanding
share of common stock,  $0.01 par value,  of Lancit (the "Lancit  Common Stock")
will be converted into the right to receive the Merger Consideration (as defined
in the Merger  Agreement) in accordance  with the terms of such  Agreement,  the
undersigned  holders (each, a  "Shareholder")  of shares of Lancit Common Stock,
severally  and not jointly,  agree with the Company as follows (all  capitalized
terms not otherwise defined herein have the respective meanings set forth in the
Merger Agreement):

     1.   During the  period  (the  "Agreement  Period")  beginning  on the date
          hereof and ending on the earlier of (i) the Effective Time (as defined
          in the  Merger  Agreement),  (ii) the date  that is 1 year  after  the
          termination of the Merger Agreement in accordance with Section 7.01(c)
          (in the case of a termination  by the Company for a willful  breach by
          Lancit of its obligations under the Merger Agreement), (e), (f) or (g)
          thereof (and, in the case of termination pursuant to subsection (e) or
          (f), payment in full of all amounts payable to the Company pursuant to
          Section 4.09 of the Merger  Agreement),  (iii) the date of termination
          of the Merger  Agreement  for any other  reason and (iv)  February 27,
          2000,  the  Shareholder  hereby  agrees  to vote all of its  Shares to
          approve and adopt the Merger  Agreement and the Merger  (provided that
          such Shareholder  shall not be required to vote in favor of the Merger
          Agreement  or the  Merger if the Merger  Agreement  has,  without  the
          consent  of such  Shareholder,  been  amended  in any  manner  that is
          material and adverse to such Shareholder) and any actions directly and
          reasonably   related  thereto  at  any  meeting  or  meetings  of  the
          shareholders of Lancit, and at any adjournment  thereof or pursuant to
          action by written consent,  at or by which such Merger  Agreement,  or
          such other actions,  are submitted for the  consideration  and vote of
          the  shareholders of Lancit so long as such meeting is held (including
          any  adjournment  thereof)  or written  consent  adopted  prior to the
          termination of the Agreement  Period.  For purposes of this Agreement,
          "Shares"  shall  mean any and all  shares of Lancit  Common  Stock now
          owned  and/or   subsequently   acquired  by  the  Shareholder  through
          purchase,  gift,  stock splits,  stock dividends and exercise of stock
          options.

     2.   During the Agreement  Period,  the  Shareholder  hereby agrees that it
          will vote all of its Shares  against the approval of any other merger,
          consolidation,  sale  of  assets,  reorganization,   recapitalization,
          liquidation  or  winding  up of  Lancit  or  any  other  extraordinary
          transaction   involving  Lancit  or  any  matters  related  to  or  in
          connection therewith.

     3.   From the date  hereof  until  the  termination  hereof,  except in its
          capacity as an officer or director  of Lancit and in  accordance  with
          Section  4.09 of the  Merger  Agreement,  the  Shareholder  will  not,
          directly or  indirectly,  (i) take any action to solicit,  initiate or
          encourage any  Acquisition  Proposal or (ii) engage in negotiations or
          discussions  with, or disclose any nonpublic  information  relating to
          Lancit or any Subsidiary or afford access to the properties,  books or
          records  of  Lancit  or  any  Subsidiary  to,  or  otherwise   assist,
          facilitate  or  encourage,  any Third  Party  that may be  considering
          making,  or has made, an Acquisition  Proposal.  The Shareholder  will
          promptly notify the Company after receipt of any Acquisition  Proposal
          or any indication  from any Third Party that it is considering  making
          an  Acquisition  Proposal  or any request  for  nonpublic  information
          relating to Lancit or any Subsidiary or for access to the  properties,
          books or records of Lancit or any  Subsidiary  by any Third Party that
          may be considering  making,  or has made, an Acquisition  Proposal and
          will keep the Company fully  informed of the status and details of any
          such Acquisition Proposal, indication or request.

     4. The Shareholder  agrees not to exercise any rights  (including,  without
limitation,  under Section 910 of the BCL) to demand  appraisal of any shares of
Lancit Common Stock owned by the Shareholder.

     5.   The Shareholder  hereby represents and warrants to the Company that as
          of the date hereof:

          (a)  the Shareholder (i) owns beneficially all of the Shares set forth
               opposite the  Shareholder's  name in Schedule A hereto,  (ii) has
               the full and  unrestricted  legal power,  authority  and right to
               enter into, execute and deliver this Voting Agreement without the
               consent or approval of any other person and (iii) has not entered
               into any voting  agreement  with or granted  any person any proxy
               (revocable  or  irrevocable)  with respect to such Shares  (other
               than this Voting Agreement).

          (b)  This Voting  Agreement is the valid and binding  agreement of the
               Shareholder.

          (c)  No  investment  banker,   broker  or  finder  is  entitled  to  a
               commission  or fee from the  Shareholder  or Lancit in respect of
               this Agreement based upon any arrangement or agreement made by or
               on behalf of the  Shareholder  except as  disclosed  pursuant  to
               Section 2.15 of the Merger Agreement.

     6.   If any  provision  of  this  Voting  Agreement  shall  be  invalid  or
          unenforceable   under   applicable   law,  such  provision   shall  be
          ineffective to the extent of such invalidity or unenforceability only,
          without in any way affecting  the remaining  provisions of this Voting
          Agreement.

     7.   This Voting Agreement may be executed in two or more counterparts each
          of  which  shall  be an  original  with  the  same  effect  as if  the
          signatures hereto and thereto were upon the same instrument.

     8.   The parties hereto agree that if for any reason any party hereto shall
          have failed to perform its  obligations  under this Voting  Agreement,
          then  the  party  seeking  to  enforce  this  Agreement  against  such
          non-performing  party shall be entitled  to specific  performance  and
          injunctive and other equitable relief,  and the parties hereto further
          agree to waive any requirement for the securing or posting of any bond
          in  connection  with the  obtaining  of any  such-injunctive  or other
          equitable  relief.  This  provision is without  prejudice to any other
          rights or remedies, whether at law or in equity, that any party hereto
          may have against any other party hereto for any failure to perform its
          obligations under this Voting Agreement.

     9. This Voting  Agreement  shall be governed by and construed in accordance
with the laws of the State of New York.

     10.  The Shareholder will, upon request, execute and deliver any additional
          documents  deemed by the  Company  to be  necessary  or  desirable  to
          complete and effectuate the covenants contained herein.

     11.  This Agreement  shall  terminate upon the termination of the Agreement
          Period.

     12.  This Agreement shall bind each Shareholder only in such  Shareholder's
          capacity  as a  shareholder  of Lancit  and only with  respect  to the
          specific  matters  set  forth  herein,  and  shall  not  prohibit  the
          Shareholder from acting in accordance with the Shareholder's fiduciary
          duties as an officer or director of Lancit.

     13.  The Shareholder agrees that if it sells, transfers, assigns, encumbers
          or otherwise disposes (each a "Transfer") of any Shares (whether to an
          affiliate or otherwise)  during the term of this  Agreement,  it shall
          require  the  transferee  of such Shares to execute and deliver to the
          Company and Lancit a voting agreement identical in form to this Voting
          Agreement  except  for the  identity  of the  Shareholder  prior to or
          concurrent  with the  consummation  of such Transfer.  The Company and
          Lancit  understand  and  acknowledge  that,  subject to the  preceding
          sentence, the Shareholder is free to Transfer any Shares at such times
          and in such manner as it deems appropriate.

     IN WITNESS WHEREOF,  the parties hereto have executed this Voting Agreement
as of this 27th day of February, 1998.


                               RCN CORPORATION


                            By  /s/ PAUL SIGMUND
                               ----------------------------------------------
                               Name:  Paul Sigmund
                               Title: Executive Vice President


                               LME ACQUISITION
                               CORPORATION

                                /s/ PAUL SIGMUND
                            By ----------------------------------------------
                               Name: Paul Sigmund


                               LANCIT MEDIA
                               ENTERTAINMENT, LTD.


                            By  /s/ SUSAN L. SOLOMON
                               ----------------------------------------------
                               Name:  Susan L. Solomon
                               Title: Chairman of the Board and Chief 
                                        Executive Officer


                               Cecily Truett

                                /s/ CECILY TRUETT
                               ----------------------------------------------
                               Name: Cecily Truett


                               Laurence A. Lancit

                                /s/ LAURENCE A. LANCIT
                               ----------------------------------------------
                               Name: Laurence A. Lancit


                               THE LANCIT CHILDREN'S TRUST

                                /s/ PAULA J. BOZE
                           By: ----------------------------------------------
                                   Name:  Paula J. Boze,
                                   Title: as sole Trustee



                                   SCHEDULE A
                                   ----------



                                                          Shares of Lancit
Shareholder                                                 Common Stock
- -----------                                                 ------------
Cecily Truett                                                  553,113
Laurence A. Lancit                                             553,113
The Lancit Children's Trust                                    40,080