How to become a singing street performer

I'm writing this as a currently active busker on the London Underground licenced busking scheme, but also a singer and violinist who has performed on the streets for years, but also played in a signed band on joules Holland, Top of the pops, and done many recordings. and who earns a lot of her money as an on line session violinist and singer.
In a way, singing on the lisenced busking scheme is easier than general street performing because the hardest barrier to initialy overcome is simply having the guts to stand up separating yourself from the general public by virtue of doing this, and performing when you haven't necessarily been invited to do so or even been given permission to do so by any one. Finding the pitch, and finding the confidence without feeling you have to disguise yourself by wearing a wig and fake prosthetic face. The only way to overcome this is by
1 preparing yourself and being ready with your set, your equipment and attitude, we will talk about this later..and also not being so extreme about this as to not accept you will mess up and learn and can't avoid that. It's a balance.
2 knowing where to play based on observing others using that pitch before and finding out from them how it is, which is location research. If it is a good pitch, someone will likely be already playing or have done it at least near by. You have to also bear in mind acoustics and how that matches with what speakers etc you have.

First thing to decide on is your set and if you are singing to backing tracks or accompanying yourself. If singing to backing tracks you can feel more under pressure to be a "proper singer" so you don't feel like a "karaoke singer", where as with an instrument ie guitar, it can help to take the pressure off for some. If you feel under these subtle psychological pressures, I can't help because it is a quandry I have also grappled with and not yet resolved. There are benefits and dis advantages to each choice. If you do go the backing track route, my advice is go for as many piano only or guitar only backings where possible as the effect will be simpler clearer and less muddied as people listen. If you pick backing arranged tracks, then pick songs that don't have too much going on in the choruses as your voice and small sound system will get swamped by distorted guitars and layered backing vocals and this is your portable system. It wont cope in te way a large system will. On u tube and I tunes there are many good backings and many terrible ones. You must be prepared to spend a good few days or weeks of trawling through and if you don't know the difference, find some one who does. And then you have to learn the songs! And all lyrics. Not a small task.And you constantly add to and change the set for your own sanity so you don't get bored.
The second thing is buying the right equipment. If you want a decent portable sound using backing tracks or if playing keyboards, which does in my opinion require stereo, it wont be cheap. If you don't go the route I suggest then you will have a battery operated crate amp or cube and believe me the backings will not sound as good. How ever, if you are accompanying your singing with you on guitar then consider getting a crate amp and then all you need is a mic and mic stand. But if going the route I have taken,the either piano accompanying or backing tracks route, you need a couple of decent but small pa speakers. I reccomend Jolly speakers, bi amped speakers, 60 watts each, made in Italy, nothing like them on the market in terms of size and weight and power, and quality for the small size, and any more than 60 watts and you wont last long on your battery, which has to be a Tracer Lithium Ion battery 22 amp hours 12 volts DC. These are a couple of hundred pounds but the alternative is eight kilos of sealed lead acid batteries and a bad back. you will also need an invertor, a small box to turn the 12 volts DC into 250 v ac. you plug your speakers and mixer into an exension plub board then into the invertor and it powers everything for at least four hours. Mixer wise, you need a low end mini mixer like a berringer they are abot righty ponds and have basic reverbs on and you plug in your mic, and backing track running off either an I pod or a cd player. CD platers by Sony tend to have higher out puts than an I pod, and a better sound, but if you change tracks manually you can often get a loud bleep which you cant alter and is very loud when played through your p.a. so this is personal choice. You need a decent live mic. Sure Beta SM58 is good or anything you like above that level. A good very warm meaty smooth mic is the Audio Technica Artist Elite AE 6100 which like the sure beta does not need phantom power, or the Audio Technica AE5400 which needs phantom power from your little mixer but your battery will deal with that no problem and the difference in drain on it will be very minimal. Which also means that if you like the Neumann KMS live vocal mics (a bit brighter and more expensive but not beter just different to the Audio Technicas) that need phantom power you can use them, but do
try out as many as you can before choosing as expensive is not always better for every body as we all have different voices. If confused by choice then start with a second hand Sure Beta SM58 which you can sell on very easily later and up grade or experiment in your own time.
Now to transport your speakers and mixer, etc, you will need an old lay style shopping trolley or childrens buggy. And as a street performer if you're interested in street credibility, a singer who likes to check her make up in the mirror over a beautiful hand bag wearing high heels...she will have to go temporarily as the life of a street performer is one of pushing old lady trolley about, of setting up speakers and fiddling with wires in the middle of a crowded street..and if you can do that, a normal stage a normal gig, stage fright..pfffft..a thing of the past. I you can be a street performer you can psychologically deal with anything and it gives you a public nonchelant armour of steel. A protective inner stregnth to last a life time and affect all areas of your life. You meet and mix with the strangest wierdest and sometimes nicest people. and you learn that what you are perceived as by others is utterly meaningless and really doesn't matter. And then, you get people telling you how amazingly you sing, and you get the best singing practice there is. Performing consistently for a few hours at a time, and being paid to do it. Priceless