The Licensing Act 2003 does not require a music licence at a street party unless amplified music is one of the main purposes of the event. However, should the event include the sale of alcohol or food, or include a publicised programme of performance then appropriate licences/notices would be required.
There is sometimes some form of 'performance' by an amateur resident or by children. But this is normally 'incidental' to the event and there is normally no money involved and the public outside the street is not invited as there is no publicity. The 'performance' is not the main focus or the reason for the event and music is background for the day.
You do not have to register a lottery (which includes raffles, sweepstakes and tombolas) if you are running an 'incidental lottery', but tickets must be sold at the event and prizes cannot be rolled over from one event to another.
The Gambling Commission's website has more information about running a lottery.
However, if you plan to sell alcohol you will need to check whether you need a Temporary Event Notice.