Alan's Ramblings - drumming tag

EletroAxé with Carlinhos Brown

Fri, 01 Apr 2011 17:17:00 GMT

Carlinhos Brown is a colossus in Brazilian music, known not only for his solo musical career but also for the founding of Timbalada and for reviving the use of the Timbau, one of the instruments I (try to!) play. As part of this year's carnival in Salvador, Kyle McDonald and Lucas Werthein built him a drum suit, with a series of drum triggers linked up to an Arduino and then via wireless to a PC to allow Carlinhos to trigger drum samples by tapping on the pads on the suits. It's a cool project, see the video below and the project page on Lucas's site for the full details.

The very first version of my wireless-controlled LED system was intended to be used on drums, so the EletroAxé project is based on a similar concept. In my case I built a prototype using a vibration sensor mounted on one of the Alfaias that we play in Juba do Leão, the Maracatu group I'm a member of. It worked fine, but then the folks from the Travelling Light Circus came along with their proposal, and the idea of mounting the strips on drums got shelved. However it would be pretty cool to link up something like that suit to the LED system. and as both are arduino-based, it wouldn't be particularly hard either. I have mad visions of this bunch playing at night, all lit up with radio-synchronised LED strips :-)

Manchester Day

Tue, 22 Jun 2010 19:38:00 GMT

On Sunday we played in the Manchester Day parade. Seemingly about 75,000 people watched, so it's probably our biggest audience yet. There are loads of pictures of us on flickr, and the costumes looked fab so all the work was worthwhile. My only gripe is it wasn't really a traditional Manchester parade as it didn't rain :-)

Hosting a community website using Solaris and Tomcat

Mon, 27 Nov 2006 02:54:59 GMT

Outside of work I'm also a member of a Community-based Samba band, Meninos do Morumbi Oldham, along with my son James. Like most people in the IT business, once people figure out what you do you inevitably get requests to help with anything related to computers, and I got collared to set up a website for the group. I started looking around for hosting providers, and my original choice was bluehost.com, based on the recommendation of my colleague Phil. However, the membership management application I'm also developing is written in Java, which mean I really wanted to run Tomcat on the site as well, and bluehost didn't offer that option. Finding a hosting provider who would host Tomcat at a reasonable price proved incredibly difficult - the costs were way more than a non-profit like us could afford. Eventually I stumbled across mod3, a UK-based hosting provider who offer a Solaris 10 zone for the princely sum of £9.95 per year, plus pay-as-you-go for network bandwidth, disk space etc. The fact that they were running Solaris appealed to me, and I was happy to risk the £10 involved out of my own capacious pocket ;-) The base hosting package also came with 660Mb of usable disk space, which was plenty for our needs.

After purchasing the site domain name and hosting I started to think about what I wanted to put on the site. You get 64Mb of RSS memory with a base zone config, which meant I needed to be fairly careful with what I ran on the site. As I said, I knew I'd probably want use Tomcat at some point, so I began to wonder if I could run the whole thing with Tomcat alone. From previous experience of setting up similar websites before, I know that setting up the site is relatively easy, the real problem is providing content, then keeping it up-to-date and relevant. I also didn't want to become the bottleneck for making changes to she site, which pretty much meant that I needed to use some sort of Content Management System, so that I could give other members of the group the ability to edit content. Nearly everyone in the organisation is a non-IT type (one of the attractions of the group for me ;-), so whatever I used had to make editing easy - requiring that people hack on raw HTML was a non-starter.

As part of the day job I'm looking at the possibility of using a CMS for part of the OpenSolaris website, so I'd already been looking around at what was available (and free!). I didn't need an 'Enterprise level' CMS - features such as versioning, content staging, multilingual support or workflow management weren't necessary, what I needed was something easy for users to understand, and that didn't have huge resource requirements. And being written in Java was a bonus, as it meant I could then run it under the Tomcat instance I already knew I was going to need for the membership management stuff.

My final choice was MeshCMS, and I've been extremely happy with it. It hit all the key requirements that I had - simple to deploy (single WAR file, no database required), easy to customise, structures the site using the directory/subdirectory paradigm that any PC user is already familiar with, has an integrated WYSIWYG editor for editing content, and the clincher - has very modest resource requirements and fits inside my 64Mb RSS constraint. MeshCMS has been exceedingly well thought out - designing the look and feel of the site involves just modifying a single JSP template, which is then applied to all the pages. The site navigation menus are all automatically generated from the layout of the directory hierarchy used to store the page content, and most-frequently accessed pages bubble to the top of the menus. Linking to other pages in the site is easy - the integrated editor provides a dynamically-generated list of pages that you can select from. The editor even provides a list of the styles defined in the site stylesheet for you to select from - a feature that Roller (the package used to run blogs.sun.com) could well do with emulating.

Having decided on the CMS, the next task was to see if I could minimise Tomcat's footprint as far as possible. Tomcat runs as a normal Unix process, and so doesn't have permission to open low-numbered ports (below 1024), which is why by default it runs on port 8080. Webservers normally run on port 80, and using that port requires root privilege. The Apache webserver gets around this problem by starting up as root, opening port 80 then switching user to the webserver user before starting to serve pages. However Tomcat is written in Java, so Unix-centric mechanisms like switching user aren't an option. The normal way to get around this is to put Tomcat behind Apache, using the mod_jk module to shunt traffic between the two. However because of my memory constraints, I wanted to avoid using Apache if at all possible. There are a number of fairly vile hacks for doing this for Linux, including stuff such as firewall or userland port redirection, but most of them suffer from various problems.

However because I was running on Solaris, I had a far better option. I was already intending to run Tomcat as a SMF service, and one of the lesser-known features of SMF is that it is integrated with the Least Privilege mechanism in Solaris 10, which allows you to grant elevated privileges to normal user processes in a controlled way. This meant that allowing Tomcat to open port 80 simply required granting it the net_privaddr privilege:

    <method_credential user='meninos' group='staff' privileges='basic,net_privaddr' />

The really neat thing is that I didn't have to give the meninos user the net_privaddr privilege permanently, it only needs it for the duration of the service start method.

So, if you are ever in the Greater Manchester area, check out our performances page on the website and if you get a chance, pop by and hear us play ;-) We were out busking in Manchester yesterday, and for once the weather was kind, despite the time of year :-)

May bank holiday busk

Mon, 01 May 2006 11:35:46 GMT

As I'd explained in a previous post, Meninos do Morumbi Oldham, the Samba band of which my son James and myself are members are going to be busking in Manchester on the last weekend of every month, with the money going to a housing project in Sao Paulo. Yesterday it was that busking time of the month again ;-) Kickoff was 11:30am at the junction of St Mary's Gate and Market Street, outside M&S in Manchester. We had an even better turnout than last time, especially of the dancers - Yay for the dancers! ;-). Unfortunately someone was already playing where we played last time, so we moved up to the other corner of M&S.

The M&S store manager appeared as we were setting up, but she was OK with us playing there after Leon explained we were only going to play 2 sets there before moving on up Market Street. Between when we started at about 12:00pm and when we finished at around 4:30pm we moved steadily up Market Street towards Piccadilly Gardens, playing a couple of times at each spot. On a couple of ocassions we caused Market Street (one of Manchester's main shopping precincts) to almost come to a standstill with a crowd of several hundred listening to us play, which was cool :-) Leon has been busking in Manchester for many years and he made a point of asking the street traders if they were OK with us playing before we started - the nice people in the burger van on the corner of Market Street and Spring Gardens got a large 'thank you' cheer as a result. Unfortunately the weather forecast was wrong and the Weather Gods frowned on us, so we got a bit wet as the day progressed, but hey, it's Manchester after all :-)

We ended up in Piccadilly Gardens and I didn't think we would draw much of a crowd there, but people quickly appeared as we started to play - well I suppose we are rather loud :-) After we'd finished playing we took some photos for the band website that is going to be set up for us by the person who did the Brazilian Meninos do Morumbi website, if you haven't already done so you should check it out - click through the entrance page and click on the 'English' link on the bottom right of the page for all you non-Portuges speakers :-) After humping all the kit back down Market Street to Ian's van some of us decamped to a nearby hostelry to drink a well-deserved pint or two (sitting outside in the rain, under the 'sun' umbrellas over the tables - how very British ;-) before a curry in the Northern Quarter and then catching the train home.

April Fool's busk

Mon, 03 Apr 2006 09:40:32 GMT

On Saturday we invaded Manchester for our first ever busking session - and all for a good cause. Eraldo (the guy in the red jacket in the photo above) comes from Sao Paulo in Brazil where we was a member of Meninos do Morumbi, a fantastic youth-focussed Samba school in Brazil. One of the things he did when in Brazil was to raise funding to rebuild the house of one of the kids who attended Meninos - many of the kids come from the favelas, and live in pretty grim conditions. He and the other tutors of Meninos do Morumbi in Oldham teach us all for free, and in return they asked that we give up one Saturday a month to either busk or play at a performance, with all the money going to a charity that they are setting up to help improve more people's housing in Sao Paulo. I think it's a superb idea - many of the bands who busk in Manchester do so for themselves, but to be honest when the money is split between all the players it probably doesn't provide more than a couple of pints each. And as Eraldo, Ian (white jacket, above), Holly (between Eraldo and Ian), Leon and Emily all give their time for free I think it's only right that we reciprocate and give something back in return. The fact that the money is going to Brazil is even more of a bonus - after all it's their music we are playing.

We started at about 11:30am and played through to nearly 3:30pm - certainly the longest I've ever played. The weather was typically April - a series of heavy showers with sunny spells in between, so we got wet a couple of times. We were on the corner outside M&S, and the weekly protests were going on - first the Palestinian faction turned up, shortly followed by the anti-Iraq war protesters, finally topped off by a group carrying Israeli flags. It's a regular occasion - about half a dozen police turned up out of nowhere and tried to politely keep the two sides out of arm's reach of each other. The sight of two men standing 5 feet apart bellowing at each other through loudhailers seemed to neatly sum up the entire Middle East situation. However I did think the air horn that one of the Israeli supporters kept letting off whenever one of the other side tried to talk was an arms escalation too far. At one point one of the policemen sidled over to us and asked if we could play really loudly and we were only too glad to oblige. It had the required effect - whilst we were playing they all shut up - well, they didn't have a hope in hell of being heard over us. I felt quite the child of the 60s ;-)

The plan is for us to busk every month, so we've got quite a few dates lined up:

Sunday 30th April, outside M&S in Manchester, 12:00am - 4:00pm
Saturday 20th May, outside M&S in Manchester, 11:00am - 3:00pm
Sunday 20th May, Oldham Carnival (May Parade)
Saturday 24th June, busking, location TBD
Saturday 29th July, busking, location TBD
Saturday 26th August, busking, location TBD

So come along. And bring money :-)